# Textbook English: A Corpus-Based Analysis of the Language of EFL Textbooks used in Secondary Schools in France, Germany and Spain

Elen Le Foll

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Elen Le Foll. Textbook English: A Corpus-Based Analysis of the Language of EFL Textbooks used in Secondary Schools in France, Germany and Spain. Linguistics. Osnabrück University, 2022. English.
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<figure><img src="image_1.png" /></figure>
Dissertation

zur Erlangung des Doktorgrades (Dr. phil.)
des Fachbereichs Sprach- und Literaturwissenschaft
der Universität Osnabrück

zum Thema

Textbook English

A Corpus-Based Analysis of the Language
of EFL Textbooks used in Secondary Schools
in France, Germany and Spain

vorgelegt von

Elen Le Foll

aus Rennes
<figure><img src="image_2.png" /></figure>
To my teachers and to all teachers
who believe in their students
Abstract

In secondary English as a Foreign Language (EFL) instructional contexts, textbooks constitute a major and highly influential vector of foreign language input. To date, numerous studies of the language of EFL textbooks have examined textbooks' representations of one or at most a handful of individual linguistic features each. Taken together, these studies provide valuable insights into "the kind of synthetic English" (Römer 2004a: 185) that pupils are exposed to via their school textbooks.

However, the literature review in Chapter 2 makes clear that three crucial aspects have so far been neglected. First, previous research has failed to consider interactions between the frequencies of individual linguistic features. Thus, whilst some influential studies have helped us understand how English learners can be misled by their textbooks into making unidiomatic use of specific linguistic features (e.g., progressive aspect; Römer 2005), only a multivariable approach can paint the full picture as to how "Textbook English" – as a whole – differs from the English that language learners will encounter outside the classroom. Second, prior scholarship has mostly ignored register differences between the various types of texts typically included in school foreign language textbooks. Given that school EFL textbooks frequently feature, for example, extracts from short stories, dialogues, instructions, and exercises on a single double page, this thesis argues that a meaningful analysis of Textbook English requires a register-based approach. Thirdly, previous quantitative corpus-based studies have usually been undertaken at the corpus level, e.g., comparing frequencies across an entire textbook corpus with those from a reference corpus, and have therefore failed to account for the effects of varying textbook proficiency levels or of any potential textbook author, editor, or publisher idiosyncrasies.

The present study therefore sets out to describe the linguistic content of secondary school EFL textbooks and to survey the similarities and most striking differences between the various registers of "Textbook English" and naturally occurring English of situationally similar registers with respect to a wide range of lexico-grammatical features. To this end, the Textbook English Corpus (TEC) was compiled. It comprises nine series of secondary school EFL textbooks (42 textbook volumes) used at lower secondary level in France, Germany and Spain and was manually annotated for six text registers: Conversation, Fiction, Informative texts, Instructional language, Personal correspondence and Poetry & rhyme. In addition, three reference corpora (Spoken BNC2014, Info Teens and Youth Fiction) are used as baselines for comparisons between the language of the TEC and the kind of naturally occurring English that learners can be expected to encounter, engage with, and produce themselves outside the EFL classroom. The compilation of the corpora is outlined in Chapter 3.

Methodologically, a contrastive corpus-based approach is adopted. Chapter 4 reports on a replication of Römer's (2005: Ch. 5–6) study on how the progressive aspect is represented in textbook dialogues compared to naturally occurring conversation, extended to a) include lexical and semantic analyses of the verbs featured in the progressive, and b) cover textbook fiction in addition to conversation. In a second in-depth case study, Chapter 5 explores the lexico-grammatical patterns and semantics of the verb MAKE in textbook conversation and
fiction as compared to the two corresponding target reference corpora. Both chapters point to notable disparities in the use of these features between the Conversation subcorpus of the TEC and the reference conversation corpus. By contrast, Textbook fiction is shown to present these much more authentically.

Chapters 6 and 7 explore the use of multi-dimensional analysis (MDA; Biber 1988; 1995) to model the linguistic specificities of Textbook English. Chapter 6 presents the results of two 'additive' MDAs based on Biber's (1988) model of General Spoken and Written English. The first shows that register accounts for, by far, the greatest proportion of linguistic variation within Textbook English, thus demonstrating that the language of EFL textbooks cannot be adequately modelled without considering register-based variation. By contrast, additional factors such as textbook proficiency level, series, and country of publication/use only play a marginal role in mediating intra-textbook variation. Instructional language is also shown to have very specific linguistic characteristics that set it apart from other textbook registers. The second, contrastive, additive MDA points to a major gap between Textbook Conversation and naturally occurring conversation across all textbook proficiency levels. This is followed by a methodological discussion about the limitations of the traditional MDA framework for the present study. On the basis of these, Chapter 7 proposes a revised MDA framework based on Principal Component Analysis (PCA) and extensive visualisations of the results (inspired by Neumann & Evert 2021). It is trialled with the same data to arrive at a more fine-grained and robust multi-dimensional model of Textbook English. The results of mixed-effects linear regressions modelling the dimension scores of textbook texts and of their corresponding reference corpora largely corroborate those of the two additive MDAs. Together with multi-dimensional visualisations, they are used to explain and illustrate the linguistic specificities of Textbook English.

Chapter 8 provides a summary and general discussion of the results of the four analysis chapters. Lexico-grammatical aspects of Textbook English that substantially diverge from the target reference corpora are highlighted with examples before turning to the study's pedagogical and methodological implications. Suggestions are made as to how teachers, textbook authors and editors could use freely available corpus data and tools to source and modify authentic texts. The case is made for a register approach (see also Rühlemann 2008) to EFL teaching and learning, and implications for teacher training and materials design are discussed. Finally, future research avenues are outlined. These include the triangulation of the present results with learner corpus data to investigate the impact of Textbook English on EFL learners' productive competences.
Zusammenfassung

Im Unterricht für Englisch als Fremdsprache in der Sekundarstufe I spielen Lehrwerke eine zentrale Rolle als Quelle fremdsprachlichen Inputs. Bisher wurde die Sprache der Englischlehrbücher jedoch nur in Bezug auf einzelne linguistische Merkmale untersucht. Diese einschlägigen Untersuchungen liefern grundsätzlich wertvolle Erkenntnisse über „the kind of synthetic English“ (Römer 2004a: 185), mit dem Schüler*innen in Lehrbüchern konfrontiert werden.

Dennoch geht aus dem Literaturüberblick (Kap. 2) hervor, dass die bisherige Forschung drei zentrale Aspekte vernachlässigt. Erstens blieb das Zusammenspiel der Häufigkeiten einzelner linguistischer Merkmale bislang unberücksichtigt. So haben wegweisende Studien gezeigt, wie Englischlernende durch die Schulbuchsprache dazu verleitet werden, bestimmte linguistische Merkmale (wie bspw. die Verlaufsform, vgl. Römer 2005) unidiomatisch zu verwenden. Um einen umfassenden Eindruck zu gewinnen, wie sich das „Schulbuchenglisch“ als Ganzes von dem Englisch unterscheidet, dem Lernende außerhalb des Unterrichts begegnen, ist ein multivariabler Ansatz notwendig. Zweitens wurden die verschiedenen Register, die Lehrwerke für den Fremdsprachenunterricht üblicherweise enthalten, bislang nicht differenziert untersucht. Da solche Lehrbücher auf nur einer Doppelseite oft Textauszüge bspw. aus Dialogen, Kurzgeschichten, Arbeitsanweisungen und Übungen enthalten, wird in dieser Dissertation dargelegt, dass eine aussagekräftige Analyse des Schulbuchenglischen einen Ansatz erfordert, der die Variable Register berücksichtigt. Drittens erfolgten frühere quantitative korpusanalytische Untersuchungen meist auf Gesamtkorpusebene. So wurden bspw. die Frequenzwerte eines gesamten Lehrbuchkorpus mit einem Referenzkorpus verglichen, ohne dabei jahrgangsabhängige Unterschiede im Lernniveau oder durch verschiedene Autor*innen, Herausgeber*innen und Verlage bedingte Besonderheiten der Lehrwerke zu berücksichtigen.

Ziel der vorliegenden Arbeit ist es daher, die sprachlichen Eigenschaften von Lehrwerken für den Englischunterricht in der Sekundarstufe I zu beschreiben. Hierbei soll ein Überblick über die Ähnlichkeiten und die markantesten Unterschiede zwischen verschiedenen Registern des „Schulbuchenglischen“ und den Englischregistern, die in vergleichbaren Situationen außerhalb des Unterrichts verwendet werden, hinsichtlich einer Vielzahl lexiko-grammatischer Merkmale gegeben werden. Hierzu wurde ein Schulbuchkorpus (Textbook English Corpus; TEC) bestehend aus neun Lehrwerken (42 Einzelbände) für den Englischunterricht an Sekundarschulen in Frankreich, Deutschland und Spanien erstellt und manuell hinsichtlich sechs Registern annotiert: Konversation, Fiktion, informative Texte, Aufgabenstellungen & Erklärungen, persönliche Korrespondenz und Dichtung & Reim. Zusätzlich dienen drei Referenzkorpora (Spoken BNC2014, Info Teens und Youth Fiction) als Grundlage für den Vergleich zwischen der Sprache des TEC und natürlichem Englisch, dem Lernende außerhalb des Unterrichts begegnen. Der Aufbau der Korpora wird in Kapitel 3 dargestellt.

Methodisch wird hier ein kontrastiver korpusanalytischer Ansatz zugrunde gelegt. Kapitel 4 stellt eine Replikation des Römer (2005: Kap. 5–6) vorgenommen Vergleiches des Gebrauchs der Verlaufsform in Lehrbuchdialogen und in natürlichen Gesprächen dar. Ergänzt wird diese um a) lexikalische und semantische Analysen der in der Verlaufsform verwendeten Verben
und b) die zusätzliche Betrachtung des Registers Fiktion in den Lehrbüchern des TEC. In einer zweiten detaillierten Fallstudie werden in Kapitel 5 die lexiko-grammatischen Konstruktionen sowie die Semantik des Verbs MAKE in den Dialogen und fiktionalen Texten der Lehrbücher im Vergleich zu den beiden entsprechenden Referenzkorpora untersucht. Beide Kapitel belegen erhebliche Unterschiede zwischen der Verwendung dieser Merkmale im Teilkorpus Konversation des TEC und jener im Spoken BNC2014. Dies kontrastiert mit der deutlich authentischeren Wiedergabe des Registers Fiktion in Lehrbuchtexten.

In den Kapiteln 6 und 7 wird die multidimensionale Analyse (MDA, Biber 1988; 1995) für die Modellierung der sprachlichen Besonderheiten des Schulbuchenglischen verwendet. Kapitel 6 enthält dabei die Darstellung der Ergebnisse zweier ,additiver' multidimensionaler Analysen (MDA) auf Basis von Bibers (1988) Modell des allgemeinen gesprochenen und geschriebenen Englisch. Aus der ersten Analyse ergibt sich, dass der weitaus größte Teil sprachlicher Variation innerhalb des Schulbuchenglischen auf das Register zurückzuführen ist. Dies belegt, dass eine Modellierung der Sprache in Lehrbüchern für den Englischunterricht ohne die Berücksichtigung der Registervariation nicht angemessen ist. Demgegenüber spielen Faktoren wie Unterschiede hinsichtlich Sprachstand, Verlag und Land für Variationen innerhalb eines Schulbuchs eine untergeordnete Rolle. Es zeigt sich ferner, dass sich die spezifischen sprachlichen Merkmale der Aufgabenstellungen und Erklärungen deutlich von anderen Schulbuchregistern unterscheiden. Aus der zweiten, kontrastiven ,additiven' MDA ergibt sich über alle Kompetenzniveaus der Lehrwerke hinweg ein erheblicher Unterschied zwischen Gesprächen in Schulbüchern und in natürlicher Sprache. Es folgt eine methodische Diskussion der Schwächen des klassischen MDA-Ansatzes für die vorliegende Untersuchung. Auf dieser Grundlage wird in Kapitel 7 ein modifizierter MDA-Ansatz auf Basis einer Hauptkomponentenanalyse und einer umfassenden Visualisierung der Ergebnisse (angelehnt an Neumann & Evert 2021) präsentiert. Umgesetzt wird dies mit denselben Daten, die in Kapitel 6 herangezogen wurden, um zu einem präziseren und robusteren mehrdimensionalen Modell des Schulbuchenglischen zu gelangen. Die Ergebnisse der gemischten Regressionsmodelle der Komponentenwerte von Schulbuchtexten sowie von ihren jeweiligen Referenzkorpora bestätigen diejenigen der beiden additiven MDAs. Zusammen mit den multidimensionalen Visualisierungen werden sie herangezogen, um die sprachlichen Besonderheiten des Schulbuchenglischen zu erklären.

Schließlich erfolgt in Kapitel 8 eine Zusammenfassung sowie eine allgemeine Diskussion der vier Analysekapitel. Lexiko-grammatische Aspekte des Schulbuchenglischen, die deutlich von den jeweiligen Referenzkorpora abweichen, werden hervorgehoben und mit Beispielen illustriert, bevor sich der Fokus einerseits auf fachdidaktische und andererseits auf sprachwissenschaftliche methodische Implikationen richtet. Weiterhin folgen Vorschläge, wie Lehrer*innen, Schulbuchautor*innen und Herausgeber*innen frei verfügbare Korpusdaten und -werkzeuge nutzen können, um an authentische Texte zu gelangen oder diese zu modifizieren. Ein Englischlehr- und -lernansatz, der das Register stärker berücksichtigt (vgl. Rühlemann 2008), wird angeregt und Implikationen für die Lehrer*innenbildung und die Lehrmaterialgestaltung dargestellt. Abschließend werden Perspektiven für zukünftige Forschung aufgezeigt, darunter die Triangulation der vorliegenden Ergebnisse mit Korpora von Lernendendaten zur Untersuchung des Einflusses von Schulbuchenglisch auf die Produktionskompetenz von Lernenden.
Résumé

Dans le domaine de l'enseignement de l'anglais langue étrangère (ALE) dans le secondaire,
les manuels scolaires sont un vecteur crucial des contenus linguistiques auxquels sont
exposé·e·s les apprenant·e·s. La plupart des études relatives à la langue employée dans les
manuels d'ALE n'abordent qu'un seul phénomène linguistique. Dans l'ensemble, ces études
offrent des éléments très révélateurs sur le « type d'anglais artificiel » (Römer 2004 : 185)
auquel sont exposé·e·s les élèves au travers de leurs manuels.

Cependant, comme l'explique le chapitre 2, les recherches réalisées à ce jour ont délaissé trois
aspects clés. Premièrement, elles ont omis d'étudier les interactions entre les différents
phénomènes linguistiques. Ainsi, si certaines études faisant autorité ont permis de mieux
comprendre pourquoi, sous l'influence de leur manuel scolaire, certain·e·s apprenant·e·s ont
tendance à faire un usage peu idiomatique de certains phénomènes linguistiques (l'aspect
progressif, p. ex., Römer 2005), seule une approche à variables multiples peut nous permettre
de comprendre pleinement les différences entre « l'anglais des manuels » et celui en usage
hors des salles de classe. Deuxièmement, jusqu'à présent, la question des différences de registre
entre les divers types de textes figurant dans les manuels scolaires a été largement ignorée.
Dans la mesure où les manuels d'ALE proposent, p. ex., des extraits d'histoires courtes, des
dialogues, des consignes, ainsi que des exercices sur une double page, cette thèse défendra
l'idée que toute analyse pertinente de l'anglais des manuels nécessite une prise en compte des
registres utilisés. Troisièmement, les études quantitatives sur corpus ont généralement été
réalisées au niveau du corpus dans sa globalité, p. ex. en comparant certaines fréquences dans
un corpus de manuels avec celles d'un corpus de référence. Ce faisant, elles ont négligé
l'impact des différents niveaux de compétence pour lesquels les manuels ont été conçus, ainsi
que les choix idiosyncratiques des auteur·rice·s ou directeur·rice·s de publication des manuels.

La présente étude se fixe donc pour objectif de décrire les contenus linguistiques des manuels
scolaires d'ALE du secondaire et d'examiner les ressemblances et dissemblances entre les
divers registres employés dans l'anglais des manuels et les registres contextuellement
similaires en anglais authentique, et cela au regard de toute une série de phénomènes
lexicogrammaticaux. A cette fin, nous avons créé un corpus d'anglais des manuels (Textbook
English Corpus ou TEC) à partir de neuf séries de manuels scolaires d'ALE (42 volumes)
utilisés dans les cinq premières années du secondaire en France, en Allemagne et en Espagne.
Ce corpus a été annoté manuellement en fonction des registres suivants : Conversation,
Fiction, Textes informatifs, Consignes & explications, Correspondance personnelle et Poèmes
& rimes. En complément, nous avons utilisé trois corpus de référence (Spoken BNC2014, Info
Teens et Youth Fiction) pour comparer la langue du TEC et l'anglais spontané auquel les
élèves sont susceptibles d'être exposé·e·s en dehors de leurs cours d'anglais. La composition
des corpus est décrite au chapitre 3.

Du point de vue méthodologique, l'approche adoptée est celle d'une analyse contrastive sur
corpus. Le chapitre 4 présente une reprise de l'étude de Römer (2005 : ch. 5-6) sur la manière
dont l'aspect progressif s'emploie dans les dialogues des manuels par rapport au discours
spontané. L'étude a été étendue sur deux points : a) une analyse lexicale et sémantique des
verbes utilisés au progressif et b) la prise en compte du registre de la fiction dans les manuels.
Au travers d'une deuxième étude de cas approfondie, le chapitre 5 examine les phénomènes lexicogrammaticaux et les aspects sémantiques liés au verbe MAKE dans les conversations et les fictions des manuels par rapport aux deux corpus de référence correspondants. Ces deux chapitres mettent en lumière d'importantes disparités quant à l'emploi de ces phénomènes entre le sous-corpus Conversation du TEC et le corpus de conversation de référence. La fiction dans les manuels, quant à elle, en offre une représentation bien plus authentique.

Les chapitres 6 et 7 passent au crible l'utilisation de l'analyse multidimensionnelle (Biber 1988 ; 1995) pour modéliser les spécificités linguistiques de l'anglais des manuels. Le chapitre 6 présente les résultats de deux analyses multidimensionnelles basées sur le modèle de l'anglais général parlé et écrit de Biber (1988). La première montre que le registre est de loin la première source de variation linguistique de l'anglais des manuels, ce qui démontre que la langue employée dans les manuels d'ALE ne peut pas être modélisée correctement sans prendre en compte les variations dues au registre. En revanche, d'autres facteurs, tels que le niveau de compétence pour lequel le manuel a été conçu, la série ou son pays de publication / d'utilisation, ne jouent qu'un rôle minime pour comprendre les variations au sein d'un manuel donné. Nous avons également montré que la langue des consignes et des explications présente des caractéristiques linguistiques très spécifiques, ce qui la différencie des autres registres employés dans les manuels. La seconde analyse multidimensionnelle contrastive met en évidence un sérieux écart entre les conversations dans les manuels et les conversations spontanées, et ce, quel que soit le niveau visé par le manuel. Cette section est suivie d'une réflexion méthodologique sur les limites de l'analyse multidimensionnelle dans la cadre de la présente étude. Sur cette base, le chapitre 7 propose un cadre d'analyse multidimensionnelle révisé reposant sur l'analyse en composantes principales (ACP) et sur des visualisations détaillées des résultats (inspirées par Neumann & Evert 2021). Ce cadre est testé avec les mêmes données dans l'optique de définir un modèle multidimensionnel de l'anglais des manuels plus solide et affiné. Les résultats de modèles mixtes modélisant les scores des différentes dimensions des textes inclus dans les manuels et dans les corpus de référence corroborent largement ceux des deux analyses multidimensionnelles basées sur Biber (1988). Ils sont utilisés en complément de visualisations multidimensionnelles pour expliquer et illustrer les spécificités linguistiques de l'anglais des manuels.

Le dernier chapitre propose un résumé de l'ouvrage ainsi qu'une réflexion générale sur les résultats des quatre chapitres d'analyse. Nous y mettons en évidence, avec des exemples, les aspects lexicogrammaticaux de l'anglais des manuels qui présentent des divergences fondamentales d'avec les corpus de référence avant d'aborder les implications pédagogiques et méthodologiques de cette étude. Nous y faisons des suggestions quant à la manière dont les enseignant·e·s, les auteur·rice·s et directeur·rice·s de publication des manuels pourraient utiliser des données de corpus et des outils de corpus en libre accès pour trouver et adapter des textes plus appropriés en termes de registre. Nous y plaidons en faveur d'une approche basée sur les registres pour l'enseignement et l'apprentissage de l'ALE (cf. Rühlemann 2008) et nous y examinons les implications en matière de formation des enseignant·e·s et de conception des supports. Enfin, nous présentons diverses pistes de recherche futures, telles que la triangulation des présents résultats avec des données de corpus d'apprenant·e·s, pour examiner l'impact de l'anglais des manuels sur les compétences des apprenant·e·s d'ALE en matière de production.
## Resumen

En contextos de enseñanza de inglés como lengua extranjera (ILE) en educación secundaria, los libros de texto constituyen un factor fundamental y de extraordinaria influencia en el contacto con el idioma extranjero. Hasta la fecha, numerosos estudios sobre el lenguaje de los libros de texto de ILE han examinado las representaciones de rasgos lingüísticos aislados. En conjunto, estos estudios proporcionan una perspectiva inestimable sobre «the kind of synthetic English [el tipo de inglés sintético]» (Römer 2004: 185) al que los alumnos se ven expuestos a través de sus libros de texto.

Sin embargo, el capítulo 2 demuestra que los estudios anteriores han ignorado tres aspectos cruciales. En primer lugar, no han tenido en cuenta las interacciones entre las frecuencias de aparición de cada uno de los rasgos lingüísticos. De esta forma, si bien algunos estudios influyentes han ayudado a comprender cómo los libros de texto pueden inducir a los alumnos de inglés a usar rasgos lingüísticos específicos de forma poco idiomática (p. ej., el aspecto progresivo; Römer 2005), solo un planteamiento multivariable puede aportar una visión global de cómo el «inglés de libro de texto» difiere del inglés que los alumnos se encontrarán fuera del aula. En segundo lugar, las investigaciones previas han dejado de lado las diferencias de registro entre los distintos tipos de textos que aparecen habitualmente en los libros de texto de idiomas de los centros educativos. Dado que, con frecuencia, los libros de texto de ILE incluyen en una misma página tanto fragmentos de relatos breves como, por ejemplo, diálogos, instrucciones o ejercicios, esta tesis sostiene que un análisis coherente del inglés de libro de texto requiere un enfoque basado en el registro. En tercer lugar, los estudios cuantitativos previos basados en corpus se han realizado a nivel de corpus, p. ej., comparando las frecuencias de todo un corpus de libros de texto con las de todo un corpus de referencia y, por tanto, no han considerado diferencias entre libros de texto, como pueden ser las producidas por factores como el nivel de inglés de los libros, sus autores, redactores o editoriales.

El presente estudio se propone, por tanto, describir el contenido lingüístico de los libros de texto de ILE en educación secundaria y examinar las similitudes y las diferencias más notables entre los diversos registros del «inglés de libro de texto» y el inglés presente de forma natural en situaciones de registro similar para un amplio rango de rasgos léxico-gramaticales. Para tal fin, se ha compilado y anotado manualmente el *Textbook English Corpus* (TEC) compuesto por nueve series de libros de texto de ILE (42 volúmenes) utilizados en el primer ciclo de educación secundaria (CINE nivel 2; UNESCO 2011) en Francia, Alemania y España, que incluye seis registros de texto: conversación, ficción, textos informativos, instrucciones, correspondencia personal, así como poesía y rima. Adicionalmente, se emplean tres corpus (*Spoken BNC2014*, *Info Teens* y *Youth Fiction*) como elementos de referencia para la comparación entre el lenguaje del TEC y el inglés de situaciones reales, es decir, el que cabe esperar que los alumnos encuentren fuera del aula y que ellos mismos producirán. La composición de los corpus se describe en el capítulo 3.

En cuanto a la metodología, se adopta un enfoque contrastivo basado en corpus. El capítulo 4 documenta una réplica del estudio de Römer (2005: Cap. 5–6) sobre la forma de representar el aspecto progresivo en los diálogos de los libros de texto comparada con una conversación
real y ampliada para a) incluir un análisis de los verbos que aparecen en el aspecto progresivo, y b) abarcar la ficción de los libros de texto, además de la conversación. En un segundo estudio de casos exhaustivo, el capítulo 5 explora los patrones léxico-gramaticales y la semántica del verbo MAKE en las conversaciones y la ficción de los libros de texto con respecto a los dos corpus de referencia correspondientes. Ambos capítulos señalan disparidades notables en el uso de estos rasgos entre el subcorpus de Conversación del TEC y el corpus de referencia de conversación. En cambio, muestran que la ficción de los libros de texto los presenta de forma mucho más auténtica.

Los capítulos 6 y 7 exploran el uso del análisis multidimensional (AMD; Biber 1988, 1995) para modelar las características lingüísticas propias del inglés de libro de texto. El capítulo 6 presenta los resultados de dos ADM basados en el modelo de Inglés General Oral y Escrito de Biber (1988). El primero muestra que el registro explica, con gran diferencia, la mayor proporción de la variación lingüística presente en el inglés de libro de texto, demostrando así que el lenguaje de los libros de texto ILE no se puede modelar de forma adecuada sin considerar la variación determinada por el registro. En cambio, otros factores como el nivel de competencia de los libros y el país de publicación o de uso tienen un efecto marginal en la generación de variaciones intra-textuales. Igualmente, el lenguaje de las instrucciones que aparecen en los libros de texto demuestra tener características lingüísticas muy específicas que lo diferencian de otros registros de los libros de texto. El segundo AMD basado en Biber (1988), de índole contrastiva, señala una brecha importante entre la conversación del inglés de libro de texto y la que sucede de forma natural, independientemente del nivel de competencia. A continuación, se aborda una discusión metodológica sobre las limitaciones que supone para este estudio un marco AMD tradicional. Partiendo de estas, el capítulo 7 propone un marco AMD revisado basado en un análisis de componentes principales (ACP), así como en una amplia visualización de los resultados (inspirado en Neumann y Evert 2021). Se utilizan los mismos datos para someter a ensayo dicho AMD revisado, llegando así a dos modelos multidimensionales más robustos del inglés de libro de texto. La aplicación de modelos de regresión lineal con efectos mixtos a los valores de los textos de los libros de texto y sus correspondientes corpus de referencia en las distintas dimensiones arrojan unos resultados que corroboran ampliamente los de los AMD basados en Biber (1988). Estos modelos se emplean, junto con las visualizaciones multidimensionales, para explicar las características lingüísticas propias del inglés de libro de texto.

Por último, el capítulo 8 proporciona un resumen y una discusión general de los resultados de los cuatro capítulos dedicados a los análisis. Antes de pasar a las implicaciones pedagógicas y metodológicas del estudio, se ponen de relieve, mediante ejemplos, diversos aspectos léxico-gramaticales del inglés de libro de texto que divergen de modo sustancial del corpus de referencia. Se presentan distintas sugerencias sobre cómo profesores, autores y editores de libros de texto podrían recurrir a corpus y herramientas de corpus gratuitas para localizar y modificar textos de registro más adecuado. Se exponen asimismo los argumentos en favor de un enfoque de la enseñanza y aprendizaje de ILE basado en el registro (ver también Rühlemann 2008) y se examinan las consecuencias en la formación de los docentes y el diseño de materiales pedagógicos. Finalmente, se esbozan futuras líneas de investigación, tal como la triangulación de los presentes resultados con datos de corpus de alumnos para investigar el efecto del inglés del libro de texto en las destrezas productivas de alumnos ILE.
Acknowledgements

To begin, I would like to thank my *Doktorvater*, Dirk Siepmann, for – what I think
is fair to say – was somewhat of a leap of faith in taking me on as his PhD student!
For all the ups and downs that this journey entailed, I remain most grateful for this
wonderful opportunity. I benefitted tremendously, both academically and personally,
from his vast knowledge, mentorship, and trust. I am also very much indebted to
Peter Uhrig who took on the role of second PhD supervisor at a particularly difficult
time and from whom I learnt a great deal. Thank you both for your support and for
all your frank words of advice and wisdom over the past few years.

Before the start of the pandemic, I had the great pleasure to share an office with
Anna Fankhauser whose contagiously positive attitude and generosity played a big
part in the success of this endeavour. I could not have hoped for a better
*Doktorschwester*! Heartfelt thanks also go to Tatjana Winter who, in her capacity as
my student research assistant over several semesters, contributed to this project with
various annotation tasks and whose interest in the project led to many insightful
conversations and the first of hopefully many successful collaborations.

The truth is I have benefited, more or less directly, from the advice and scholarship
of far too many people to mention them all here. Yet, at the risk of forgetting
someone, I would like to extend special thanks to: Alexander Bergs, Alexandra
Elbakyan, Andrea Nini, Carolyn Blume, Dieter Mindt, Douglas Biber, Katharina
Delius, Larissa Goulart, Lena Heine, Luke Tudge, Martin Schweinberger, Muhammad
Shakir, Natalia Levshina, Stefan Gries, Stephanie Evert, Susanne Flach and Ute
Römer. In addition, and with some overlap, I would like to thank the conference
attendees of the Anglistentag, DGFF, ICAME, IVACS and TaLC conferences for their
kind welcome into the academic world and generous feedback on my various
presentations on this and other research projects.

Years of working remotely can be alienating and, at times, rather demoralising. As
such, I am particularly grateful to the #AcademicTwitter community –
#AcademicChatter #corpuslinguistics #TEFL #Rstats and many more – that made
#phdlife during a global pandemic considerably more enjoyable whilst giving me the
opportunity to extend my academic network and broaden my intellectual horizon
during my home-office tea breaks in ways that might not have been possible in other
circumstances.
I am eternally grateful to my “proofreading squad”<fnref n="1" />: Anja Höing, Anna Fankhauser, Barbara Oberhofer, Birgit Kohn, Charlotte Hahn, Janna Gerdes, Lisa Scheiwe, Marie-Christine Benen, Nathan Dykes, Muhammad Shakir and Susanne Dyka. In addition, it would not have been possible to include translations of the abstract of the thesis in French, Spanish and German without the help of generous friends and colleagues. Un grand merci à Fiona Scuiller, Gaëtanelle Gilquin et Naomi Truan. Muchas gracias a Verónica Lasarte Prieto y Pascual Pérez-Paredes. Und herzlichen Dank an Katharina Hauptmann und Anna Fankhauser. It goes without saying that all remaining errors are mine.

This project has relied on a host of open-source software. As such, I am indebted to
the entire Open Source community. In particular, I am grateful for the work of the
good people of RStudio and Zotero and the developers of the countless R packages
and python libraries that I used as part of this project. This PhD would also not have
been possible without the contributions of the selfless heroes of Stack Overflow & the
R-Ladies community slack: I hope to be able to pay back my debt in the years to
come by helping others take their first scientific coding steps.

Last, but certainly not least, Brompton and his technician have been the most
wonderful companions on this long and sometimes arduous PhD journey: thank you
for seeing me through. To many more adventures!

<footnote n="1">¹ With thanks to Nathan Dykes for coining this term.</footnote>
# Table of Contents

## 1 INTRODUCTION .................................................................................. 1

1.1 Aims, scope and methodology..................................................................................1

1.2 English as a foreign language at secondary school level........................................3

1.3 Authenticity in EFL teaching......................................................................................6

1.4 Usage-based theories to L2 learning and teaching................................................8

1.5 Input and frequency........................................................................................................10

1.6 Input in lower secondary school EFL contexts..........................................................11

1.7 Textbooks in the EFL classroom..................................................................................12

1.8 Corpus linguistics and foreign language education..................................................18

1.9 Outline of the thesis........................................................................................................20

## 2 LITERATURE REVIEW ........................................................................ 23

2.1 Part One: Methodological review ........................................................................25

2.1.1 Intra-textbook approaches ..................................................................................25

2.1.1.1 Checklist approach to textbook evaluation........................................................25

2.1.1.2 Page-by-page intra-textbook analysis.................................................................26

2.1.1.3 Corpus-based intra-textbook analysis.................................................................26

2.1.2 Comparative approaches.........................................................................................28

2.1.2.1 Word-frequency lists approaches.................................................................29

2.1.2.2 NLP methods........................................................................................................31

2.1.2.3 Corpus-based comparisons of ‘real-life’ language to textbook language................33

2.1.2.4 Comparing textbook language to ‘real-life’ language........................................35

2.1.2.5 Elicitation approaches......................................................................................37

2.1.2.6 Adding learner corpora to the equation.................................................................38

2.1.2.7 Textbook language as learner target language..................................................40

2.1.3 Evaluating the impact of textbook language.................................................................42

2.2 Part Two: Key findings of Textbook English studies........................................44

2.2.1 Lexis .................................................................................................................................44

2.2.1.1 Individual words ..................................................................................................45

2.2.1.2 Multi-word units ..................................................................................................47

2.2.2 Tense and aspect........................................................................................................50

2.2.2.1 Future constructions .........................................................................................50

2.2.2.2 The present perfect .................................................................................................50

2.2.2.3 The progressive........................................................................................................51

2.2.2.4 Modals....................................................................................................................52

2.2.2.5 Conditionals........................................................................................................52

2.2.2.6 Reported speech........................................................................................................54

2.2.3 Pragmatics....................................................................................................................55

2.2.4 Spoken grammar........................................................................................................57

2.3 Conclusion....................................................................................................................59
3 RESEARCH AIMS AND DATA .................................................. 62

3.1 Insights from the literature review .................................................. 62

3.2 The present thesis .................................................................................. 65

3.2.1 Research aims and questions.................................................................. 65

3.2.2 Open Science statement ........................................................................ 66

3.3 Corpus data ................................................................................................. 67

3.3.1 The Textbook English Corpus (TEC) .................................................. 68

3.3.1.1 Selection of textbooks ........................................................................ 68

3.3.1.2 Textbook processing ........................................................................ 74

3.3.1.3 Corpus mark-up: headers .................................................................... 74

3.3.1.4 Register annotation ........................................................................ 75

3.3.2 The reference corpora............................................................................ 82

3.3.2.1 The Spoken BNC2014 .................................................................... 83

On the use of L1 norms in English language teaching .................................... 84

Processing of the Spoken BNC2014 .................................................................. 88

3.3.2.2 The Youth Fiction corpus .................................................................... 89

3.3.2.3 The Informative Texts for Teens Corpus (Info Teens) ......................... 91

4 EXPLORING THE PROGRESSIVE IN TEXTBOOK ENGLISH.. 95

4.1 Rationale and aims .................................................................................. 95

4.1.1 EFL learners' use of the progressive........................................................ 95

4.1.2 The progressive in EFL textbooks............................................................ 97

4.1.3 Aims and research questions .................................................................... 98

4.2 Methodology ................................................................................................. 101

4.2.1 Extraction of progressive concordance lines ............................................ 101

4.2.2 Annotation........................................................................................................ 103

4.2.2.1 Automatic pre-annotation .................................................................... 103

4.2.2.2 Semantic domains of progressive verbs................................................ 104

4.2.2.3 Manual identification of non-progressives........................................ 106

4.2.2.4 Morphosyntactic features .................................................................... 106

4.2.2.5 Functions of the progressive................................................................. 106

4.2.2.6 Validation of the annotation scheme ................................................ 108

4.2.2.7 Frequency of the progressive ............................................................ 108

4.2.3 Collostructional analysis ........................................................................ 111

4.2.3.1 Co-varying Collexeme Analyses: Verb/Semantic domain + Corpus................ 113

4.2.3.2 Comparative Distinctive Collexeme Analysis........................................ 114

4.2.4 Correspondence Analysis........................................................................ 120

4.3 Results and discussion ............................................................................ 121

4.3.1 Frequency of progressives........................................................................ 121

4.3.2 Morphosyntactic features........................................................................ 121

4.3.2.1 Tense, aspect and modality.................................................................... 122

4.3.2.2 Contractions........................................................................................ 125

4.3.2.3 Negation ............................................................................................ 127

4.3.2.4 Questions............................................................................................ 128

4.3.2.5 Voice........................................................................................................ 129

4.3.3 Functions of the progressive........................................................................ 131
<table><tr><td>4.3.3.1</td><td>Time reference</td><td>131</td></tr><tr><td>4.3.3.2</td><td>Time reference, tense and modality</td><td>135</td></tr><tr><td>4.3.3.3</td><td>(Non-)continuousness</td><td>137</td></tr><tr><td>4.3.3.4</td><td>Repeatedness</td><td>140</td></tr><tr><td>4.3.3.5</td><td>Additional functions of the progressives</td><td>141</td></tr><tr><td>4.3.4</td><td>Lexical and semantic aspects</td><td>142</td></tr><tr><td>4.3.4.1</td><td>Co-varying Collexeme Analyses of 'Verb lemma' + 'Variety'</td><td>142</td></tr><tr><td>4.3.4.2</td><td>Co-varying Collexeme Analyses of 'Semantic domain' + 'Variety'</td><td>147</td></tr><tr><td>4.3.4.3</td><td>Correspondence Analysis (CA) of 'Semantic domain' + 'Variety' + 'Register'</td><td>150</td></tr><tr><td>4.3.4.4</td><td>Distinctive Collexeme Analyses</td><td>152</td></tr></table>

<table><tr><td>4.4</td><td>Conclusion</td><td>161</td></tr></table>

<table><tr><td>5</td><td>MAKING SENSE OF MAKE IN TEXTBOOK ENGLISH</td><td>165</td></tr></table>

<table><tr><td>5.1</td><td>Rationale and aims</td><td>165</td></tr><tr><td>5.1.1</td><td>MAKE in Learner English</td><td>167</td></tr><tr><td>5.1.2</td><td>MAKE in Textbook English</td><td>168</td></tr></table>

<table><tr><td>5.2</td><td>Methodology</td><td>169</td></tr></table>

<table><tr><td>5.3</td><td>Results and discussion</td><td>171</td></tr><tr><td>5.3.1</td><td>MAKE in the Textbook English Corpus (TEC)</td><td>171</td></tr><tr><td>5.3.2</td><td>Semantics of MAKE in Textbook Conversation and Fiction</td><td>173</td></tr><tr><td>5.3.3</td><td>MAKE in the prototypical 'produce' sense</td><td>176</td></tr><tr><td>5.3.4</td><td>MAKE as a delexical verb</td><td>181</td></tr><tr><td>5.3.5</td><td>Phrasal verbs with MAKE</td><td>185</td></tr><tr><td>5.3.6</td><td>Causative MAKE</td><td>188</td></tr></table>

<table><tr><td>5.4</td><td>Conclusions</td><td>192</td></tr></table>

<table><tr><td>6</td><td>A MULTI-DIMENSIONAL DESCRIPTION OF TEXTBOOK ENGLISH</td><td>195</td></tr></table>

<table><tr><td>6.1</td><td>Introduction</td><td>195</td></tr><tr><td>6.1.1</td><td>Multi-feature/multi-dimensional analysis (MDA)</td><td>196</td></tr><tr><td>6.1.2</td><td>MDA and textbook language</td><td>207</td></tr><tr><td>6.1.2.1</td><td>Exploring Textbook English using Additive MDA</td><td>207</td></tr><tr><td>6.1.2.2</td><td>Exploring Textbook English by conducting a full MDA</td><td>209</td></tr></table>

<table><tr><td>6.2</td><td>Method</td><td>210</td></tr><tr><td>6.2.1</td><td>Choosing a baseline MDA study</td><td>210</td></tr><tr><td>6.2.2</td><td>Defining text units in the TEC</td><td>211</td></tr><tr><td>6.2.3</td><td>Tagging and counting features</td><td>213</td></tr><tr><td>6.2.4</td><td>Computing the mean dimension scores for the new registers</td><td>214</td></tr><tr><td>6.2.5</td><td>Computing dimension scores for additional reference corpora</td><td>214</td></tr><tr><td>6.2.6</td><td>Comparing dimension scores</td><td>215</td></tr></table>

<table><tr><td>6.3</td><td>Results</td><td>219</td></tr><tr><td>6.3.1</td><td>Intra-textbook linguistic variation</td><td>220</td></tr></table>
<table><tr><td>8.2.3</td><td>Towards a register approach to teaching EFL</td><td>388</td></tr><tr><td>8.2.4</td><td>Implications for teacher education</td><td>391</td></tr><tr><td>8.2.5</td><td>Implications for materials design</td><td>396</td></tr><tr><td>8.3</td><td>Limitations and methodological implications</td><td>400</td></tr><tr><td>8.4</td><td>Future research avenues</td><td>403</td></tr><tr><td>8.5</td><td>Conclusion</td><td>404</td></tr><tr><td colspan="2">REFERENCES</td><td>406</td></tr><tr><td colspan="2">APPENDICES</td><td>452</td></tr></table>
List of Figures

<table>
  <tbody>
    <tr>
      <td>Fig. 1: Proportion of tokens in the three “national” subcorpora the TEC (as displayed by Sketch Engine; Kilgarriff et al. 2014)</td>
      <td>72</td>
    </tr>
    <tr>
      <td>Fig. 2: Proportion of tokens in each register category on the TEC</td>
      <td>79</td>
    </tr>
    <tr>
      <td>Fig. 3: Composition of the web corpus originally retrieved by Sketch Engine</td>
      <td>92</td>
    </tr>
    <tr>
      <td>Fig. 4: Distribution of progressive forms in Textbook Conversation and the Spoken BNC2014</td>
      <td>122</td>
    </tr>
    <tr>
      <td>Fig. 5: Association plot comparing the progressive form distributions in Textbook Conversation and the Spoken BNC2014 sample</td>
      <td>123</td>
    </tr>
    <tr>
      <td>Fig. 6: Progressive form distributions in the Spoken BNC2014 sample and the five different Textbook levels</td>
      <td>124</td>
    </tr>
    <tr>
      <td>Fig. 7: Association plot comparing the tense form distributions in Textbook Fiction and the Youth Fiction sample</td>
      <td>125</td>
    </tr>
    <tr>
      <td>Fig. 8: Proportion of contracted progressives by progressive form in Textbook Conversation as compared to the Spoken BNC2014 sample</td>
      <td>126</td>
    </tr>
    <tr>
      <td>Fig. 9: Time period reference for the progressives in Textbook Conversation and the Spoken BNC2014 sample</td>
      <td>132</td>
    </tr>
    <tr>
      <td>Fig. 10: Association plot of the distribution of time references of progressives in Textbook Conversation and the Spoken BNC2014 sample</td>
      <td>133</td>
    </tr>
    <tr>
      <td>Fig. 11: Distribution of time references of progressives in the Spoken BNC2014 sample and in Textbook Conversation for each textbook level</td>
      <td>134</td>
    </tr>
    <tr>
      <td>Fig. 12: Association plot of progressive time reference between Level C-E Textbook Conversation and the Spoken BNC2014 sample</td>
      <td>135</td>
    </tr>
    <tr>
      <td>Fig. 13: Mosaic plot displaying the cross-tabulation of forms and time references of progressives in Textbook Conversation and the Spoken BNC2014 sample (progressives with ‘unclear’ time references were removed for this analysis)</td>
      <td>136</td>
    </tr>
    <tr>
      <td>Fig. 14: Distribution of the semantic categories of verbs in the progressives across the four (sub)corpora (excluding polysemous verbs)</td>
      <td>148</td>
    </tr>
    <tr>
      <td>Fig. 15: Simple binary correspondence analysis of ‘Semantic domain’ and ‘Corpus’</td>
      <td>151</td>
    </tr>
    <tr>
      <td>Fig. 16: Comparison of the standardised CL values (scaled and centred G<sup>2</sup>) returned by the two progressive vs. non-progressive Distinctive Collexeme Analyses (DCAs). Positive values represent attraction to the progressive, negative to the non-progressive construction.</td>
      <td>154</td>
    </tr>
    <tr>
      <td>Fig. 17: Comparison of the standardised CL values (scaled and centred G<sup>2</sup>) returned by the two progressive vs. non-progressive Distinctive Collexeme Analyses (DCAs)</td>
      <td>159</td>
    </tr>
    <tr>
      <td>Fig. 18: Relative frequencies of the verb lemma MAKE in Textbook and Reference subcorpora</td>
      <td>173</td>
    </tr>
    <tr>
      <td>Fig. 19: Comparison of the distribution of MAKE meanings in Textbook Conversation and the Spoken BNC2014 sample</td>
      <td>173</td>
    </tr>
    <tr>
      <td>Fig. 20: Comparison of the distribution of MAKE meanings in Textbook Fiction and Youth Fiction</td>
      <td>175</td>
    </tr>
    <tr>
      <td>Fig. 21: Distribution of the semantic fields attributed to the noun collocates of MAKE in the (Ai) ‘produce’ sense in Textbook Conversation and the Spoken BNC2014 sample</td>
      <td>176</td>
    </tr>
    <tr>
      <td>Fig. 22: Frequent collocate lemmas of MAKE in the (Ai) ‘produce’ sense in Textbook Conversation and Spoken BNC2014 sample</td>
      <td>177</td>
    </tr>
    <tr>
      <td>Fig. 23: Differences in semantic fields attributed to collocates of MAKE in the (Ai) ‘produce’ sense.</td>
      <td>180</td>
    </tr>
    <tr>
      <td>Fig. 24: Most frequent collocates of delexical MAKE in Textbook Conversation and the Spoken BNC2014</td>
      <td>182</td>
    </tr>
    <tr>
      <td>Fig. 25: Most frequent collocates of delexical MAKE in Textbook Fiction (left) and the Youth Fiction sample (right)</td>
      <td>183</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>Fig. 26 'Speech/communication' delexical MAKE collocations in Textbook Conversation and Textbook Fiction (red) as compared to the reference Spoken BNC2014 and Youth Fiction samples (beige).</td>
      <td>184</td>
    </tr>
    <tr>
      <td>Fig. 27: The most frequent collexemes of the causative MAKE constructions of Textbook Conversation and the Spoken BNC2014 sample</td>
      <td>190</td>
    </tr>
    <tr>
      <td>Fig. 28: Correlation matrix of the normalised counts in Table 39</td>
      <td>199</td>
    </tr>
    <tr>
      <td>Fig. 29: Mean scores of general spoken and written registers of English on Biber's (1988) Dimension 1 (as summarised in Biber &amp; Conrad 2019: 292)</td>
      <td>206</td>
    </tr>
    <tr>
      <td>Fig. 30: Matrix of correlations among the estimated random effects of the maximal model: lmer(Dim2 ~ Register + Level + Level*Register + (Register|Series))</td>
      <td>217</td>
    </tr>
    <tr>
      <td>Fig. 31: Distribution of texts of the TEC on Biber's (1988) Dimension 1</td>
      <td>221</td>
    </tr>
    <tr>
      <td>Fig. 32: Observed (grey circles) and predicted (red triangle) Dimension 1 scores across textbook register, proficiency level and textbook series. Predicted values as computed by the model summarised in Table 66. (Le Foll 2021. Zenodo. Retrieved on 7 May 2021. http://doi.org/10.5281/zenodo.4732323)</td>
      <td>224</td>
    </tr>
    <tr>
      <td>Fig. 33: Distribution of the texts of the TEC on Biber's Dimension 2 (excluding one outlier text from the Poetry register)</td>
      <td>229</td>
    </tr>
    <tr>
      <td>Fig. 34: Visualisation of the effects of Register*Level interactions on the estimated Dimension 2 values of the TEC texts (as calculated with the model summarised in Table 49)</td>
      <td>232</td>
    </tr>
    <tr>
      <td>Fig. 35: Distribution of the texts of the TEC on Biber's (1988) Dimension 3</td>
      <td>234</td>
    </tr>
    <tr>
      <td>Fig. 36: Estimated scores on Biber's (1988) Dimension 3 subdivided by register and textbook series</td>
      <td>238</td>
    </tr>
    <tr>
      <td>Fig. 37: Distribution of the texts of the TEC on Biber's (1988) Dimension 4 (with one outlier from the Informative register removed)</td>
      <td>239</td>
    </tr>
    <tr>
      <td>Fig. 38: Estimated mean Dimension 4 scores subdivided per textbook register and proficiency level</td>
      <td>241</td>
    </tr>
    <tr>
      <td>Fig. 39: Distribution of the texts of the TEC on Biber's (1988) Dimension 5</td>
      <td>242</td>
    </tr>
    <tr>
      <td>Fig. 40: Distribution of the texts of the TEC on Biber's (1988) Dimension 6</td>
      <td>244</td>
    </tr>
    <tr>
      <td>Fig. 41: Estimated scores on Biber's (1988) Dimension 6 across levels C to E textbooks</td>
      <td>247</td>
    </tr>
    <tr>
      <td>Fig. 42: Comparison of the Conversation, Fiction and Informative texts from the TEC with the three corresponding target language reference corpora on Biber's (1988) Dimension 1 (as calculated by the MAT, see below)</td>
      <td>248</td>
    </tr>
    <tr>
      <td>Fig. 43: Comparison of scores on Biber's (1988) Dimension 1 of the Spoken BNC2014 and Textbook Conversation, recalculated so as to exclude the features that rely on punctuation marks for their operationalisation</td>
      <td>250</td>
    </tr>
    <tr>
      <td>Fig. 44: Estimated varying effects of textbook series on modified Dimension 1 scores for Textbook Conversation (simulated using the R function merTools::REsim; Knowles &amp; Frederick 2020)</td>
      <td>254</td>
    </tr>
    <tr>
      <td>Fig. 45: Informative textbook text with a low Dimension 1 score &lt;TEC: Join the Team 4&gt;</td>
      <td>255</td>
    </tr>
    <tr>
      <td>Fig. 46: Comparison of the Conversation, Fiction and Informative texts from the TEC with the three corresponding target language reference corpora on Biber's (1988) Dimension 2</td>
      <td>257</td>
    </tr>
    <tr>
      <td>Fig. 47: Normalised frequencies of features loading on Biber's (1988) Dimension 2 for Textbook Fiction (subdivided by proficiency level A to E) and Youth Fiction</td>
      <td>260</td>
    </tr>
    <tr>
      <td>Fig. 48: Comparison of the Conversation, Fiction and Informative texts from the TEC with the three corresponding target language reference corpora on Biber's (1988) Dimension 3</td>
      <td>261</td>
    </tr>
    <tr>
      <td>Fig. 49: Per-feature accuracy measures of the MFTE on the TEC, the Spoken BNC2014 and data comparable to the Youth Fiction and Info Teens</td>
      <td>279</td>
    </tr>
    <tr>
      <td>Fig. 50: The ten most frequent word forms occurring immediately after if in the Spoken BNC2014 (as counted and displayed by Sketch Engine, see https://ske.li/nu8 for full results)</td>
      <td>282</td>
    </tr>
    <tr>
      <td>Fig. 51: Distribution of normalised frequencies of occurrence of five features across the TEC (histograms) and visualisations of their correlation (scatterplots)</td>
      <td>290</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>Fig. 52: Distribution of signed log transformed standardised normalised frequencies of occurrence of five features across the TEC (histograms) and visualisations of their correlation (scatterplots)</td>
      <td>292</td>
    </tr>
    <tr>
      <td>Fig. 53 Correlation matrix of the signed log standardised relative frequencies of the features analysed in the second PCA-based MDA (see 7.3.2)</td>
      <td>295</td>
    </tr>
    <tr>
      <td>Fig. 54: Dimension 1 mean scores for disciplines (left) and genre families (right) from Gardner et al.</td>
      <td>299</td>
    </tr>
    <tr>
      <td>Fig. 55: Scree plot of the eigenvalues of the principal components (PCs) for the TEC data</td>
      <td>303</td>
    </tr>
    <tr>
      <td>Fig. 56: Snapshots from the 3-D visualisation of the first three dimensions of the multi-dimensional model of intra-textbook variation</td>
      <td>304</td>
    </tr>
    <tr>
      <td>Fig. 57: Scatterplot matrix of combinations of the first six dimensions of the model of intra-textbook variation (the number before the comma on each axis label shows which principal component is plotted on that axis; this is followed by the percentage of the total variance explained by that particular component)</td>
      <td>305</td>
    </tr>
    <tr>
      <td>Fig. 58: Projection of the texts of the TEC on the first and second dimensions of the model of intra-textbook variation</td>
      <td>307</td>
    </tr>
    <tr>
      <td>Fig. 59: Graph of the features with the strongest contributions to the first and second dimensions of the model of intra-textbook variation</td>
      <td>307</td>
    </tr>
    <tr>
      <td>Fig. 60: Projection of the texts of the TEC on the third and fourth dimensions of the model of intra-textbook variation</td>
      <td>309</td>
    </tr>
    <tr>
      <td>Fig. 61: Graph of the features with the strongest contributions to the third and fourth dimensions of the model of intra-textbook variation</td>
      <td>309</td>
    </tr>
    <tr>
      <td>Fig. 62: Projection of the texts of TEC on third and fourth dimensions with colours and ellipses indicating the proficiency level of the textbooks (as opposed to register as in Fig. 60)</td>
      <td>311</td>
    </tr>
    <tr>
      <td>Fig. 63: Projection of the texts of the TEC on the fifth and sixth dimensions of the model of intra-textbook variation</td>
      <td>311</td>
    </tr>
    <tr>
      <td>Fig. 64: Coefficient estimates and 95% confidence intervals of the fixed effects in the model: lmer(PC1 ~ Register + (1|Series)) (the intercept corresponds to the reference level: Register [Conversation])</td>
      <td>315</td>
    </tr>
    <tr>
      <td>Fig. 65: Coefficient estimates and 95% confidence intervals of the fixed effects in the model: lmer(PC2 ~ Register + Level + Register*Level + (1|Series)). The reference levels are Register [Conversation] and Level [A]</td>
      <td>319</td>
    </tr>
    <tr>
      <td>Fig. 66: Estimated PC2 scores across each register and the five textbook proficiency levels</td>
      <td>321</td>
    </tr>
    <tr>
      <td>Fig. 67: Coefficient estimates and 95% confidence intervals of the fixed effects in the model: lmer(PC3 ~ Register + Level + Register*Level + (1|Series)). The intercept corresponds to the reference levels Register [Conversation] and Level [A]</td>
      <td>323</td>
    </tr>
    <tr>
      <td>Fig. 68: Estimated PC3 scores across each register and the five textbook proficiency levels</td>
      <td>324</td>
    </tr>
    <tr>
      <td>Fig. 69: Coefficient estimates and 95% confidence intervals of the fixed effects in the model: lmer(PC4 ~ Register + Level + Register*Level + (1|Series)). The reference levels are Register [Conversation] and Level [A]</td>
      <td>326</td>
    </tr>
    <tr>
      <td>Fig. 70: Estimated PC4 scores across each register and the five textbook proficiency levels</td>
      <td>327</td>
    </tr>
    <tr>
      <td>Fig. 71: Scree plot of the eigenvalues of the PCs for the Textbook English vs. 'real-life' English PCA</td>
      <td>328</td>
    </tr>
    <tr>
      <td>Fig. 72: Snapshots from the 3-D representation of texts along PC1-PC3</td>
      <td>329</td>
    </tr>
    <tr>
      <td>Fig. 73: Scatterplot matrix of combinations of the four dimensions of the model of Textbook English vs. 'real-life' English (the number before the comma on each axis label shows which principal component is plotted on that axis; this is followed by the percentage of the total variance explained by that particular component)</td>
      <td>330</td>
    </tr>
    <tr>
      <td>Fig. 74: Projection of the texts of the three subcorpora of the TEC and the reference corpora on PC1 and PC2</td>
      <td>332</td>
    </tr>
    <tr>
      <td>Fig. 75: Graph of the features with the strongest contributions to the first and second dimensions</td>
      <td>332</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>Fig. 76: Projection of the texts of the three subcorpora of the TEC and the reference corpora on PC3 and PC4</td>
      <td>335</td>
    </tr>
    <tr>
      <td>Fig. 77: Projection of the texts of the three subcorpora of the TEC and the reference corpora on PC3 and PC4 with ellipses representing the five textbook proficiency levels vs. the reference corpora</td>
      <td>335</td>
    </tr>
    <tr>
      <td>Fig. 78: Predicted PC3 scores of the texts of the TEC and the reference corpora</td>
      <td>337</td>
    </tr>
    <tr>
      <td>Fig. 79: Features that make the most important contributions to the third and fourth dimensions</td>
      <td>338</td>
    </tr>
    <tr>
      <td>Fig. 80: Predicted PC4 scores of the texts of the TEC and the reference corpora</td>
      <td>340</td>
    </tr>
    <tr>
      <td>Fig. 81: Predicted PC1 scores of the texts of the TEC and the reference corpora</td>
      <td>342</td>
    </tr>
    <tr>
      <td>Fig. 82: Predicted PC2 scores of the texts of the TEC and the reference corpora</td>
      <td>350</td>
    </tr>
    <tr>
      <td>Fig. 83: Normalised counts of selected features with salient loadings on PC1 in the Textbook Informative subcorpus (Levels A to E) and the reference Info Teens corpus (Ref.)</td>
      <td>352</td>
    </tr>
    <tr>
      <td>Fig. 84: Proportion of tokens in each register category of the French subcorpus of the TEC (as displayed by Sketch Engine; Kilgarriff et al. 2014)</td>
      <td>356</td>
    </tr>
    <tr>
      <td>Fig. 85: Cumulative word counts of the Conversation, Fiction, Instructional, Informative, Personal correspondence and Poetry texts for each of the 42 textbook volumes of the TEC</td>
      <td>357</td>
    </tr>
    <tr>
      <td>Fig. 86: Projection of texts on PC1 and PC2 from a random 2/3 split-data analysis of the three subcorpora of the TEC and the three reference corpora</td>
      <td>365</td>
    </tr>
    <tr>
      <td>Fig. 87: Projection of texts on PC3 and PC4 from a random 2/3 split-data analysis of the three subcorpora of the TEC and the three reference corpora</td>
      <td>365</td>
    </tr>
    <tr>
      <td>Fig. 88: Exercise featured below (254)</td>
      <td>383</td>
    </tr>
    <tr>
      <td>Fig. 89: Grammar box featured below (254)</td>
      <td>383</td>
    </tr>
    <tr>
      <td>Fig. 90: Word frequency analysis with english-corpora.org (on the basis of COCA data) of excerpt (255)</td>
      <td>384</td>
    </tr>
    <tr>
      <td>Fig. 91: Part of the ‘word sketch’ page of the word <i>lush</i> as generated on english-corpora.org/coca</td>
      <td>385</td>
    </tr>
    <tr>
      <td>Fig. 92: Word frequency analysis with english-corpora.org (on the basis of COCA data) of excerpt (254)</td>
      <td>386</td>
    </tr>
    <tr>
      <td>Fig. 93: Part of the “word sketch” page of the word <i>moreover</i> on english-corpora.org/coca</td>
      <td>386</td>
    </tr>
  </tbody>
</table>
List of Tables

<table>
  <tbody>
    <tr>
      <td>Table 1: Distribution of the articles <i>a</i>, <i>an</i> and <i>the</i> in the five Malaysian textbooks examined by Mukundan et al. 2012 (as reported in Table 1, p. 69) and in the BNC1994 (as calculated by Sketch Engine on 13.10.2018) in raw numbers and as a % of articles</td>
      <td>27</td>
    </tr>
    <tr>
      <td>Table 2: Comparison of the order of the most frequent prepositions in the BNC1994 and three Malaysian ESL textbooks</td>
      <td>31</td>
    </tr>
    <tr>
      <td>Table 3: The levels of the Textbook English Corpus (TEC)</td>
      <td>69</td>
    </tr>
    <tr>
      <td>Table 4: Most widely used lower secondary school textbook series (and publisher in brackets) according to the informal market surveys conducted with teachers, bookshop assistants and publishers in France, Germany and Spain</td>
      <td>70</td>
    </tr>
    <tr>
      <td>Table 5: Composition of the Textbook English Corpus (TEC) (the full bibliographic metadata is available on doi.org/10.5281/zenodo.4922819)</td>
      <td>73</td>
    </tr>
    <tr>
      <td>Table 6: Number of words per textbook register categories in the TEC (as calculated by Sketch Engine Kilgarriff et al. 2014)</td>
      <td>79</td>
    </tr>
    <tr>
      <td>Table 7: Summary of the regular expressions (regex) used to process the Spoken BNC2014 (see Online Appendix 3.3 for full script)</td>
      <td>89</td>
    </tr>
    <tr>
      <td>Table 8: Composition of the Informative Texts for Teen Corpus</td>
      <td>93</td>
    </tr>
    <tr>
      <td>Table 9: Core and additional function categories for the progressive (all examples from Römer 2006b: Appendix)</td>
      <td>107</td>
    </tr>
    <tr>
      <td>Table 10: Example contingency table for the verb SAY in the first CovCA conducted (see 4.2.3.1)</td>
      <td>114</td>
    </tr>
    <tr>
      <td>Table 11: Last three entries of the count table for the conversation register before normalisation</td>
      <td>116</td>
    </tr>
    <tr>
      <td>Table 12: Contingency table for SAY in Textbook Conversation (the figures in bold were directly counted from the subcorpus)</td>
      <td>116</td>
    </tr>
    <tr>
      <td>Table 13: Contingency table for SAY in the Spoken BNC2014 sample (the figures in bold have been directly counted, underlined approximated from the corpus)</td>
      <td>117</td>
    </tr>
    <tr>
      <td>Table 14: Examples of lemmas whose non-progressive FVP counts were negative in the Spoken BNC2014</td>
      <td>118</td>
    </tr>
    <tr>
      <td>Table 15: Example lemma frequency counts for the Spoken BNC2014 after having adjusted for sampling/tagging errors</td>
      <td>119</td>
    </tr>
    <tr>
      <td>Table 16: Contingency table for SAY in the Spoken BNC2014 post-adjustments</td>
      <td>119</td>
    </tr>
    <tr>
      <td>Table 17: Proportion (and raw numbers) of contracted forms of the auxiliary BE in progressive constructions</td>
      <td>126</td>
    </tr>
    <tr>
      <td>Table 18: Proportions of contracted and non-contracted progressives in Textbook Fiction and the Youth Fiction corpus</td>
      <td>127</td>
    </tr>
    <tr>
      <td>Table 19: Proportion of negated progressives in Textbook Conversation and the Spoken BNC2014 sample</td>
      <td>127</td>
    </tr>
    <tr>
      <td>Table 20: Proportion of negated progressives in Textbook Fiction texts and the Youth Fiction sample</td>
      <td>127</td>
    </tr>
    <tr>
      <td>Table 21: Voice of progressive constructions</td>
      <td>130</td>
    </tr>
    <tr>
      <td>Table 22: The continuousness function of progressives in the two textbook registers and reference corpora</td>
      <td>138</td>
    </tr>
    <tr>
      <td>Table 23: Most frequent lemmas occurring in the progressive with a 'non-continuous' function in Textbook Conversation and the Spoken BNC2014 (total occurrences in 'non-continuous' function) (as a percentage of all progressive occurrences)</td>
      <td>139</td>
    </tr>
    <tr>
      <td>Table 24: The repeatedness function of progressives in the two textbook registers and reference corpora as a percentage of all progressives (and in absolute figures)</td>
      <td>140</td>
    </tr>
    <tr>
      <td>Table 25: Percentages of progressives within each (sub)corpus coded for additional functions (raw figures are given in brackets)</td>
      <td>141</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>Table 26: Top 20 Co-varying Collexemes for 'Verb' + 'Variety' (Spoken BNC2014 vs. Textbook Conversation)</td>
      <td>143</td>
    </tr>
    <tr>
      <td>Table 27: Top 10 Co-varying Collexemes for 'Verb' + 'Variety' (Textbook Fiction vs. Youth Fiction sampled)</td>
      <td>146</td>
    </tr>
    <tr>
      <td>Table 28: Results of the CovCA 'Semantic domain' + 'Variety' (Textbook Conversation vs. reference Spoken BNC2014 sample)</td>
      <td>149</td>
    </tr>
    <tr>
      <td>Table 29: Eight most frequent 'communication' verbs in the Spoken BNC2014 progressive concordance sample (n = 370)</td>
      <td>149</td>
    </tr>
    <tr>
      <td>Table 30: Results of the CovCA of 'Semantic domains' + 'Fiction Varieties' (Textbook Fiction vs. Youth Fiction sample)</td>
      <td>150</td>
    </tr>
    <tr>
      <td>Table 31: Most significantly distinctive collexemes associated with the progressive (positive G<sup>2</sup> values) and the non-progressive constructions (negative G<sup>2</sup> values) in Textbook Conversation and the Spoken BNC2014 sample</td>
      <td>153</td>
    </tr>
    <tr>
      <td>Table 32: Top 30 verb lemmas with the greatest absolute difference in attraction/repulsion CL scores to the progressive in Textbook Fiction and the Youth Fiction Corpus (negative values in the second and/or third columns represent repulsion of the progressive, in other words, attraction to non-progressive constructions)</td>
      <td>158</td>
    </tr>
    <tr>
      <td>Table 33: Semantic categories of MAKE according to the VDE (Herbst, Heath &amp; Roe 2013) illustrated with sentences from the TEC</td>
      <td>170</td>
    </tr>
    <tr>
      <td>Table 34: Frequency of the verb lemma MAKE in the TEC</td>
      <td>172</td>
    </tr>
    <tr>
      <td>Table 35: Distribution of the most frequent idioms featuring MAKE in Textbook Conversation and the Spoken BNC2014 sample (absolute frequencies)</td>
      <td>174</td>
    </tr>
    <tr>
      <td>Table 36: Absolute frequencies of phrasal verbs with MAKE (out of 674 occurrences of MAKE each for the Conversation samples and 392 for the two Fiction samples)</td>
      <td>186</td>
    </tr>
    <tr>
      <td>Table 37: Causative MAKE constructions in the Textbook Conversation and Spoken BNC2014 sample</td>
      <td>189</td>
    </tr>
    <tr>
      <td>Table 38: Linguistic features used in Biber's (1988) MDA of general English (as categorised and listed in Conrad &amp; Biber 2013: 18-19)</td>
      <td>197</td>
    </tr>
    <tr>
      <td>Table 39: Selected normalised feature counts (per 100 words in three texts (see excerpts (179)-(181) below))</td>
      <td>199</td>
    </tr>
    <tr>
      <td>Table 40: Features with a minimum factor loading of ±0.35 that make up Biber's (1988) seven-factor solution</td>
      <td>202</td>
    </tr>
    <tr>
      <td>Table 41: The computation of dimension scores on the basis of normalised frequencies</td>
      <td>204</td>
    </tr>
    <tr>
      <td>Table 42: The computation of dimension scores on the basis of standardised frequencies (z-scores)</td>
      <td>204</td>
    </tr>
    <tr>
      <td>Table 43: Summary of Biber's six dimensions of English (1988)</td>
      <td>205</td>
    </tr>
    <tr>
      <td>Table 44: Distribution of Textbook English Corpus (TEC) texts processed in this chapter</td>
      <td>213</td>
    </tr>
    <tr>
      <td>Table 45: Summary of the model: lmer(Dim1 ~ Register + Level + Level*Register + (1|Series))</td>
      <td>222</td>
    </tr>
    <tr>
      <td>Table 46: Estimated register means of Dimension 1 scores (averaged across all textbook levels)</td>
      <td>226</td>
    </tr>
    <tr>
      <td>Table 47: Estimated differences between mean Dimension 1 scores for each TEC register pair (averaged across all textbook levels)</td>
      <td>226</td>
    </tr>
    <tr>
      <td>Table 48: Mean z-scores of the features that load on Biber's (1988) Dimension 1</td>
      <td>227</td>
    </tr>
    <tr>
      <td>Table 49: Summary of the model: lmer(Dim2 ~ Register + Level + Level*Register + (1|Series))</td>
      <td>229</td>
    </tr>
    <tr>
      <td>Table 50: Estimated Dimension 2 means and 95% confidence intervals (CI)</td>
      <td>233</td>
    </tr>
    <tr>
      <td>Table 51: Summary of the model: lmer(Dim3 ~ Register + Level + Level*Register + (1|Series))</td>
      <td>234</td>
    </tr>
    <tr>
      <td>Table 52: Summary of the model: lmer(Dim4 ~ Register + Level + Level*Register + (1|Series)) (excluding the outlier discussed above)</td>
      <td>240</td>
    </tr>
    <tr>
      <td>Table 53: Mean Dimension 5 scores for Informative texts grouped by textbook level</td>
      <td>243</td>
    </tr>
    <tr>
      <td>Table 54: Summary of the model: lmer(Dim5 ~ Register + Level + Level*Register + (1|Series)) for Levels C to E textbook texts only</td>
      <td>243</td>
    </tr>
    <tr>
      <td>Table 55: Summary of the model: lmer(Dim6 ~ Register + Level + Level*Register + (1|Series)) for levels C to E textbooks only</td>
      <td>246</td>
    </tr>
  </tbody>
</table>
<table>
  <tbody>
    <tr>
      <td>Table 56: Summary of the model: lmer(Dim1<sub>adjusted</sub> ~ 1 + Corpus + Register + Corpus*Register + (Register|Source))</td>
      <td>250</td>
    </tr>
    <tr>
      <td>Table 57: Normalised counts for the features loading on Biber's (1988) Dimension 1, except those that rely on punctuation for their operationalisations (features with positive loadings in red and bold, with negative loadings in blue)</td>
      <td>251</td>
    </tr>
    <tr>
      <td>Table 58: Summary of the model: lmer(Dim2 ~ 1 + Corpus + Register + Corpus*Register + (Register|Source))</td>
      <td>258</td>
    </tr>
    <tr>
      <td>Table 59: Estimated Dimension 2 means (degrees-of-freedom method: asymptotic)</td>
      <td>258</td>
    </tr>
    <tr>
      <td>Table 60: Summary of the model: lmer(Dim3 ~ 1 + Corpus + Register + Corpus*Register + (1|Source))</td>
      <td>261</td>
    </tr>
    <tr>
      <td>Table 61: Estimated mean Dimension 3 scores (degrees-of-freedom method: asymptotic)</td>
      <td>262</td>
    </tr>
    <tr>
      <td>Table 62: Textbook English Corpus (TEC) texts processed in this chapter</td>
      <td>272</td>
    </tr>
    <tr>
      <td>Table 63: Excerpt of Appendix I: Operationalisation of the 'DO as an auxiliary' feature</td>
      <td>275</td>
    </tr>
    <tr>
      <td>Table 64: Summary of the terminology used in tagger performance evaluation</td>
      <td>277</td>
    </tr>
    <tr>
      <td>Table 65: Most frequent tagging error types</td>
      <td>280</td>
    </tr>
    <tr>
      <td>Table 66: Summary of the model: lmer(PC1 ~ Register + Level + Level*Register + (1|Series))</td>
      <td>312</td>
    </tr>
    <tr>
      <td>Table 67: Estimated differences between mean PC1 scores for each TEC register pair (averaged across all textbook levels and series)</td>
      <td>314</td>
    </tr>
    <tr>
      <td>Table 68: List of feature loadings (eigenvectors) on the four dimensions of the model of intra-textbook variation</td>
      <td>315</td>
    </tr>
    <tr>
      <td>Table 69: List of feature loadings (eigenvectors) in the Textbook English vs. 'real-life' English PCA-based model</td>
      <td>333</td>
    </tr>
    <tr>
      <td>Table 70: Summary of the model: lmer(PC3 ~ 1 + Level + Register + Level*Register + (1|Source))</td>
      <td>336</td>
    </tr>
    <tr>
      <td>Table 71: Summary of the model: lmer(PC1 ~ 1 + Level + Register + Level*Register + (Register|Source))</td>
      <td>341</td>
    </tr>
    <tr>
      <td>Table 72: Summary of the model: lmer(PC2 ~ 1 + Level + Register + Level*Register + (1|Source))</td>
      <td>348</td>
    </tr>
  </tbody>
</table>
List of Abbreviations

<table><tr><td>BNC</td><td>British National Corpus</td></tr><tr><td>CA</td><td>Correspondence analysis (see 4.2.4)</td></tr><tr><td>CL</td><td>Collostructional strength (see 4.2.3)</td></tr><tr><td>COCA</td><td>Corpus of Contemporary American English</td></tr><tr><td>CovCA</td><td>Co-varying collexeme analysis (see 4.2.3.1)</td></tr><tr><td>DCA</td><td>Distinctive collexeme analysis (see 4.2.3.2)</td></tr><tr><td>EAP</td><td>English for academic purposes</td></tr><tr><td>EFA</td><td>Exploratory factor analysis (see 7.2.5)</td></tr><tr><td>EFL</td><td>English as a foreign language (see 1.1)</td></tr><tr><td>EGP</td><td>English for general purposes</td></tr><tr><td>ELF</td><td>English as a lingua franca (see 3.3.2.1)</td></tr><tr><td>ENL</td><td>English as a native language (see 1.1)</td></tr><tr><td>ESL</td><td>English as a second language (see 1.1)</td></tr><tr><td>ESP</td><td>English for specific purposes</td></tr><tr><td>FA</td><td>Factor analysis (see 7.2.5)</td></tr><tr><td>FPV</td><td>Finite verb phrase (see 4.2.2.7)</td></tr><tr><td>Info Teens</td><td>Informative Texts for Teens Corpus (see 3.3.2.3)</td></tr><tr><td>L1</td><td>First language(s) (see 1.1)</td></tr><tr><td>L2</td><td>Second or more (foreign) language (see 1.1)</td></tr><tr><td>MAD</td><td>Median absolute deviation</td></tr><tr><td>MFTE</td><td>Multi-feature tagger of English (see 7.2.2)</td></tr><tr><td>PCA</td><td>Principal component analysis (see 7.2.5)</td></tr><tr><td>pmw</td><td>per million words</td></tr><tr><td>POS</td><td>Part of speech</td></tr><tr><td>SD</td><td>Standard deviation</td></tr><tr><td>TEC</td><td>Textbook English Corpus (see 3.3.1)</td></tr><tr><td>VDE</td><td>Valency Dictionary of English (Herbst, Heath & Roe 2013)</td></tr><tr><td>Youth Fiction</td><td>Youth Fiction Corpus (see 3.3.2.2)</td></tr></table>

Note that the full list of the linguistic features tagged by the MFTE and their abbreviations (see Chapter 7) can be found in Appendix I.
# 1 Introduction

> [T]he reason that coursebooks are so often in the line of fire is that they
do to a large extent dominate and determine so many aspects of a
teacher's day-to-day professional life.

❖ Scott Thornbury (2012)

Asked “Where is Brian?”, French nationals of a certain generation will immediately
reply: “Brian is in the kitchen”. Those with a particularly good memory may follow
up with: “Where is Jenny, the sister of Brian?” – and, to those in the know, the
correct answer is: “Jenny is in the bathroom”.<fnref n="2" /> Clearly, there is no need for any in-
depth linguistic analysis to conclude that this interaction is highly unlikely to have
ever taken place in a real English-speaking family home. To most teachers and
learners, it will be evident that it is the result of a none too inspired attempt to model
WH-question forms in a beginner textbook dialogue aimed at learners of English as a
Foreign Language (EFL). Together with dull gap-fill exercises and photos of out-of-
date technology, for many adults, the very mention of the word textbook evokes vivid
memories of such artificially sounding, contrived and sometimes even non-sensical
dialogues.

This raises the question of the status and nature of textbook language as a specific
'variety' of language, which is the subject of the present study. It focuses on
contemporary EFL textbooks in use in European secondary schools. Situated at the
interface between linguistics and foreign language education, it examines the linguistic
content of these textbooks and seeks empirical answers to the questions: What kind
of English do school EFL textbooks portray? And how far removed is this variety of
English from the kind of English that learners can be expected to encounter outside
the EFL classroom?

## 1.1 Aims, scope and methodology

The above questions are critical because, as many adults’ lingering memories of school
foreign language lessons testify (see also, e.g., Freudenstein 2002: 55), textbooks play
an absolutely central role in classroom-based foreign language learning. In the
following, we will see that the dominance of textbooks in EFL school contexts persists
to this day. According to Thornbury (2012 in a comment response to Chong 2012:
n.p.), they “(more often [than] not) instantiate the curriculum, provide the texts, and
- to a large extent - guide the methodology”.

<footnote n="2">² Dialogue from *Speak English 6e série verte* (Benhamou & Dominique 1977: 167). It was made popular by stand-up comedian Gad Elmaleh.</footnote>
In lower secondary EFL instructional contexts, in particular, textbooks constitute a major vector of foreign language input. Yet, numerous studies have shown that “considerable mismatches between naturally occurring English and the English that is put forward as a model in pedagogical descriptions” (Römer 2006a: 125–126) exist. These mismatches have been observed and sometimes extensively described in textbooks’ representations of numerous language features ranging from the use of individual words and phraseological patterns (e.g., Conrad 2004 on the preposition *though*; Gouverneur 2008a on the high-frequency verbs *make* and *take*), to tenses and aspects (e.g., Barbieri & Eckhardt 2007 on reported speech; Römer 2005 on the progressive). More rarely, textbook language studies have also ventured into the study of spoken grammar (e.g., Gilmore 2004) and pragmatics (e.g., Hyland 1994 on hedging in ESP/EAP textbooks). As will be shown in Chapter 2, previous EFL textbook studies have tended to focus on one or at most a handful of individual linguistic features. Taken together, they provide valuable insights into “the kind of synthetic English” (Römer 2004a: 185) that pupils are exposed to via their textbooks; yet, what is missing is a more comprehensive, broader understanding of what constitutes “Textbook English” from a linguistic point of view. In particular, although corpus-based<fnref n="3" /> textbook analysis can be traced back to the pioneering work of Dieter Mindt in the 1980s, the language of secondary school EFL textbooks (as opposed to that of general adult EFL or English for Specific Purposes [ESP] coursebooks) remains an understudied area.

The present study therefore sets out to describe the linguistic content of secondary school EFL textbooks and to survey the similarities and most striking differences between “Textbook English” and “naturally occurring English” with respect to a wide range of lexico-grammatical features. To this end, a corpus of nine series of secondary school EFL textbooks (42 textbook volumes) used at lower secondary level in France, Germany and Spain was compiled (see 3.3.1). In addition, three reference corpora are used as baselines for comparisons between the language input EFL learners are confronted with via their school textbooks and the kind of naturally occurring English that they can be expected to encounter, engage with, and produce themselves on leaving school. Two of these have been built specifically for this project with the aim of representing comparable ‘authentic’ (for a discussion of this controversial term in ELT, see 1.3) and age-appropriate learner target language.

As hinted at in the title, a bottom-up, corpus-based approach is adopted (e.g., Mindt 1992; 1995a; Biber & Quirk 2012; Biber & Gray 2015; Carter & McCarthy 2006a). Various corpus-linguistic methods are used to analyse the linguistic specificities of Textbook English. A broad range of linguistic features ranging from tenses and

<footnote n="3">³ In the present work, the adjectives ‘corpus-based’ and ‘corpus-driven’ are used synonymously (see, e.g., Meunier & Reppen 2015: 499 for further information as to how these terms are sometimes distinguished).</footnote>
aspects to negation and discourse markers are examined in both quantitative and qualitative contrastive analyses. Lexico-grammatical aspects of Textbook English that substantially diverge from the target learner language reference corpora are highlighted and illustrated with direct comparisons of textbook excerpts with comparable texts from the reference corpora.

The rest of this chapter briefly outlines the underlying pedagogically-driven and
theoretical motivations for this study beginning with the status of English as a foreign
language (EFL)<fnref n="4" /> at secondary school level with a focus on continental Europe. This
is followed by a summary of some of the controversies around the contentious concept
of ‘authenticity’ in 1.3. An overview of the linguistic and language development
theories that motivated the present study is represented in 1.4, followed by a section
highlighting the centrality of input in foreign language learning and teaching in 1.5.
Section 1.6 turns to language input in lower secondary school EFL contexts in
particular, whilst 1.7 focuses on secondary school EFL learners’ main source of English
input: their textbooks. Finally, Section 1.8 situates the present study and its
methodological framework within the growing body of “pedagogically-driven corpus-
based research” (Gabrielatos 2006: 1). This introductory chapter concludes with an
outline of the rest of the thesis in 1.9.

## 1.2 English as a foreign language at secondary school level

As the most widely taught foreign language and the lingua franca of choice in business and academia, the upmost relevance of English as a Foreign Language (EFL) in the 21st century need not be explained. In mainland Europe, too, English is by far the most widely taught foreign language. At lower secondary school level, defined here as ISCED 2 (UNESCO Institute for Statistics 2012; 2015) (see also 3.3.1.1), almost all students (97.3% according to the latest available figures from 2014) attend English classes (European Commission, EACEA, & Eurydice 2017: 13).

<footnote n="4">⁴ Note that, throughout this thesis, the term ‘English as a foreign language’ (EFL) is used to refer to learning English in countries and regions where English is not an official or otherwise widely used language (e.g., France, Germany and Spain). For non-native English speakers learning English in countries/regions where English is an official or widely used language, the term ‘English as a second language’ (ESL) is preferred. Where both learning contexts are meant, English ‘L2’ is used, regardless of whether English is in fact an individual’s second, third, or more non-native language. The author recognises that all of these terms – ‘native’ vs. ‘non-native’ or ‘foreign’ and ‘L1’ vs. ‘L2’ – are inherently problematic with regards to their epistemology, operationalisations and underlying assumptions (see, e.g., Birkland et al. 2022; Holliday 2005; Ramjattan 2019). For lack of a better generalisable categorisation system, however, the terms ‘English native speaker’/‘English L1 user’ and ‘EFL learner’/‘English L2 user’ are used throughout the present thesis as an imperfect means to differentiate between two typically very different language acquisition contexts in full recognition that such a dichotomisation represents a vast over-simplification of what are frequently much more complex language biographies and learning experiences.</footnote>
In Germany, English is a mandatory subject during compulsory secondary education in nine out of the sixteen *Bundesländer* (European Commission, EACEA, & Eurydice 2017: 44). As of 2013, 97.8% of students were learning English in the *Sekundarstufe I*. Similarly high rates were recorded in France (98.6%) and Spain (100%) in 2016 (European Commission, EACEA, & Eurydice 2017: 164). Across Europe, a clear upward trend in the proportion of students learning English in compulsory school education can be observed for the period between 2005 to 2014 (European Commission, EACEA, & Eurydice 2017: 77).

In France and Germany, the expected minimum level of attainment based on the Common European Framework of Reference for Languages (hereafter CEFR; Council of Europe 2020) is B1 by the end of lower secondary, and B2 by the end of general upper secondary, whilst in Spain it is A2 and B1 respectively (European Commission, EACEA, & Eurydice 2017: 122–123). This difference in target proficiency level is reflected in the minimum annual instruction time for EFL as a compulsory subject: in the eighth year of compulsory schooling, it ranges from 111 hours in Spain to 154 in Germany and 216 in France (European Commission, EACEA, & Eurydice 2017: 107–108)<fnref n="5" />.

Up until recently, the competence-based descriptors of the CEFR made frequent mentions of an idealised native speaker as the reference point. For instance, at B2 level, learners were expected to be able to “interact with a degree of fluency and spontaneity that makes regular interaction with native speakers quite possible without strain for either party” (Council of Europe 2001: 24) and to “sustain relationships with native speakers without unintentionally amusing or irritating them or requiring them to behave other than they would with a native speaker” (Council of Europe 2001: 76). However, the updated guidelines (Council of Europe 2020), like most current European school curricula, no longer explicitly mention native speakers as the target norm.

The German Core Curriculum stresses the need for learners of English to learn to deal with authentic texts, in particular in listening and reading comprehension, as well as in mediation activities (Kultusministerkonferenz 2012: 12, 15, 18). In Spain, too, the focus lies on the transferability of competences acquired in the classroom to genuine communicative situations:

> El enfoque orientado a la acción adoptado en el currículo se concentra en el estudiante, que es quien aprende, construye sus competencias y las utiliza, tanto para llevar a cabo las tareas de aprendizaje en el aula como las que demanda la comunicación real [The action-oriented approach adopted in the curriculum focuses on the learner, who is the one who learns, builds

<footnote n="5">⁵ For Spain and Germany, these figures correspond to the weighted average instruction time as calculated on the basis of the number of students enrolled in each educational authority and type of school (European Commission, EACEA, & Eurydice 2017: 107–108).</footnote>
his or her competences and uses them, both to accomplish the learning tasks in the classroom and those afforded by real communication].<fnref n="6" /> (Consejería de Educación, Juventud y Deporte de Madrid 2015: 133)

The French curriculum also makes clear that the priority of school English instruction should be enabling students to exploit and interact with authentic materials in all language skills (Conseil supérieur des programmes 2015).

Up until recently, there was no doubt that EFL teaching was expected to follow native-speaker norms. European foreign language curricula now generally refrain from referring to any specific native-speaker varieties. For instance, the German Education Standard for the general higher education entrance level (Abitur) states that:

> Sprachlicher Orientierungspunkt sind *Standardsprache(n)* sowie Register, Varietäten und Akzente, deren Färbung ein Verstehen nicht generell behindert [The linguistic point of reference is *standard language(s)*, as well as registers, varieties and accents, whose distinctiveness do not generally impede comprehension]. (Kultusministerkonferenz 2012: 14 emphasis added).

In practice, however, this typically amounts to either a ‘standard’ British or a US-American English norm. Using similar terminology, the curriculum of the Autonomous Community of Madrid refers to “*una variante estándar de la lengua*” [a standard variety of the language] (Consejería de Educación, Juventud y Deporte de Madrid 2015: 432). At this stage, the repeated use of the word ‘standard’ begs the question: What is meant by ‘standard varieties of English’ in such educational contexts? This question has sparked controversies since at least the 1980s, when debates concerning the variety of English to be taught as part of the National Curriculum of England and Wales raged (Tony 1999: 1). Quirk (1995: 5) provided an early, succinct summary of the main concerns associated with the term ‘Standard English’:

> There are few enough (not least among professional linguists) that would claim the existence of a single standard within any one of the ENL [English L1] countries: plenty that would even deny both the possibility and the desirability of such a thing. Recent emphasis has been on multiple and variable standards (insofar as the use of the word ‘standard’ should be ventured): different standards for different occasions for different people – and each as ‘correct’ as each other.

The plurality of different ‘standard’ registers, varieties and accents to which Quirk refers is echoed in the German Education Standard cited above – as opposed to the excerpt from the Madrilenian curriculum which uses a singular article implying that a single standard variety should be taught. Regardless of whether a single or multiple ‘standards’ are to be taught, in practice, what does or does not constitute a ‘standard’ form of any widely used language is notoriously difficult to define (for book-length discussions on Standard English, see, e.g., Crowley 2003; Milroy & Milroy 2012; Tony 1999). What most linguists, education scholars and, indeed, teaching practitioners

<footnote n="6">⁶ All translations mine, unless otherwise noted.</footnote>
would likely agree on, however, is that ‘standard varieties’ can be equated to prestige varieties (Tony 1999: 7) and prestige is usually associated with ‘correctness’. This notion is confirmed in the German Education Standards, which states:

> Die Entwicklung der funktionalen kommunikativen Kompetenzen ist bezogen auf die *geläufige* und *korrekte* Verfügung über die sprachlichen Mittel in den Bereichen: Aussprache und Intonation, Orthographie, Wortschatz, Grammatik. [The development of functional communicative competence [in a foreign language] refers to the *typical/frequent* and *correct* use of linguistic features in the areas of: pronunciation and intonation, spelling, vocabulary and grammar] (Kultusministerkonferenz 2003: 9; emphases added).

Thus, in spite of not (officially) adhering to any (specific) native-speaker norm(s), the objectives set out by school educational authorities stipulate that pupils are expected to be taught *correct*, *typical*, and *frequent* English forms. Whilst measures of correctness necessarily involve some subjective judgements, objective measures of typicality and frequency of occurrence in English as it occurs naturally “in the wild” can be made on the basis of corpus data. At the same time, it is clear that such measures of frequency and typicality will differ depending on the situational context of language use. In sum, modern European secondary school curricula appear to advocate for the teaching of real-life, naturally occurring, idiomatic or, what has often been termed, “authentic” English.

## 1.3 Authenticity in EFL teaching

‘Authenticity’ is a particularly challenging concept in ELT and, in particular, in EFL contexts. Definitions abound – as do their interpretations (see Gilmore 2019 for an overview). One understanding, which is not infrequently encountered among English teachers, is that authentic input is input created by native speakers for native speakers (see, e.g., Little, Devitt & Singleton 2002). At the other end of the spectrum, some adopt very broad definitions such that essentially any text with a “true” communicative objective is deemed to be authentic (e.g., Swaffar 1985: 17). Since teaching and learning a language can easily be argued to constitute genuine communicative objectives, such definitions imply that all pedagogical texts are ‘authentic’. In practice, this is clearly not the case: learners, teachers and researchers frequently unite to deplore the contrived, artificial-sounding texts typically found in EFL textbooks, which often feature pragmatically highly unlikely sentences of the type: *Where is Jenny, the sister of Brian?, Are you swimming in the sea?*<fnref n="7" /> and *There’s grass in the garden*.<fnref n="8" />

The real crux of the problem is that authenticity can be understood either as a characteristic of a text, the participants of the text, its communicative intent, social or cultural context, or any combination of these. Hence, authenticity need not refer

<footnote n="7">⁷ From *Achievers Pre-intermediate* (see Table 5).</footnote>

<footnote n="8">⁸ From *Green Line 1* (see Table 5).</footnote>
solely to the linguistic elements of the texts presented to learners. Indeed, some
authors have (re-)defined authenticity to include the relationship of the texts offered
to the learners' culture (e.g., Prodromou 1992), learners' interaction with texts and
the tasks associated to them (e.g., Widdowson 1978), and the learners' personal
engagement with the texts (e.g., van Lier 2013). Given this wealth of definitions,
Mauranen (2004a: 201-202) suggests that it may be advantageous to distinguish
between "subjective" and "objective" authenticity. Such a distinction appears
reasonable at first glance. However, according to Mauranen, subjective authenticity
would reflect learners' perceptions of the materials, whilst teachers' and/or
researchers' evaluation would be objective. This assumption that teachers' and
researchers' evaluations are inherently objective is, however, highly questionable,
given that even foreign language education scholars cannot agree on an
operationalisable definition.

Indeed, though space precludes a detailed discussion of the many controversies around
the term and its various meanings, this very brief introduction to the issue will argue
that authenticity is simply too difficult to define for anyone to be expected to make
objective classifications (for more detailed discussions of authenticity in foreign
language teaching and materials design, see, e.g., Widdowson 1989; Mishan 2005;
Trabelsi, Tomlinson & Masuhara 2010; Tomlinson 2013a; Gilmore 2019; Nelson 2022).
Part of the problem is that many of the debates on authenticity in ELT implicitly
assume that a text either *is* or *is not* "authentic". Yet, authenticity need not be a
dichotomous variable or, indeed, a uni-dimensional one (see also Bendix 1997: 23; Day
& Bamford 1998: 58-59). That said, in the present study, the terms 'authentic', 'real-
life' and 'naturally occurring' are used synonymously to refer to texts that have not
been specifically produced nor modified or adapted with L2 learners in mind.

As for the pedagogical impact of authentic materials on L2 learners, some scholars
have argued that the simplification and contrivance of teaching materials facilitates
learning (e.g., Widdowson 1984: 218) whilst others have countered that they deprive
learners of opportunities for naturalistic learning and can therefore hamper progress
(e.g., Siepmann 2011: 29; Sinclair 1983; Wolff 1984). Others, still, have advocated for
simplified or otherwise pedagogically modified texts that nonetheless retain the
"natural qualities of authenticity" (Day & Bamford 1998: 59). The notion of 'enriched
input' (also sometimes called 'flooded input') has also been proposed: it refers to
pedagogical texts employed in a meaning-focused activity, in which a target structure
has artificially been multiplied to raise learners' awareness of the structure in context
(see, e.g., Reinders & Ellis 2009).

The most common socio-functional argument put forward by detractors of contrived
pedagogical materials is that authentic materials boost learners' motivation (e.g.,
Ahmad & Millar 2020; Gilmore 2011; Ghanbari, Esmaili & Shamsaddini 2015; Liedke
2013; Little, Devitt & Singleton 1989; Peacock 1997; Rüschoff & Wolff 1999; Sun
2010; Varmış Kiliç & Genç İlter 2015). However, others reject this argument claiming that the opposite is true: authentic texts demotivate learners because they make too many assumptions about known lexical, grammatical and cultural knowledge (e.g., Freeman & Holden 1986; Prodromou 1996; Richards 2001: 252–254; Vielau 2005; Widdowson 2003: 107).

Given how difficult it is to define (let alone: operationalise!) authenticity, conducting valid and reliable studies to measure the impact of authentic vs. non-authentic materials on learners' motivation (or, indeed, learning outcomes) constitutes a near impossible feat. Yet, motivation remains a popular argument both for and against the use of authentic materials. The textbook publishing industry has seemingly learnt to make the best of both worlds by, on the one hand, frequently plastering claims of “authentic English” and “authentic texts” on its book covers and marketing materials and, on the other, featuring plenty of pedagogically contrived texts within its coursebooks (Gilmore 2007: 106). Perhaps the most convincing claim is that acquiring the skills to engage with authentic materials may, in itself, be motivating for learners (e.g., Little, Devitt & Singleton 1989; Skehan 2014). In other words, intrinsic motivation may arise from the process of engaging with the materials, rather than the materials themselves being the cause of the motivation (see also Gilmore 2007: 108).

At any rate, knowing that authenticity is so notoriously difficult to define certainly relativises the contentious claims made by both proponents and critics of the use of authentic materials in the EFL classroom. Hence, rather than quibble over what *does* or *does not* constitute a genuinely “authentic” or “real-life” text in the EFL classroom, or to what degree, let us focus on a more relevant and, at least theoretically, operationalisable question: What kind of language do learners need to be exposed to and engage with in order to acquire typical, idiomatic English that will equip them with the linguistic, pragmatic, discourse, and sociocultural means to thrive outside the classroom? To do so, this study turns to usage-based approaches to language and language learning (see, e.g., Barlow & Kemmer 2000; Bybee & Hopper 2001; Bybee 2007; Ellis, Römer & O'Donnell 2016; Robinson & Ellis 2008; Tomasello 2005; Tyler, Ortega & Uno 2018).

## 1.4 Usage-based theories to L2 learning and teaching

A usage-based understanding of L2 learning and teaching naturally draws on a range of approaches, including various branches of usage-based linguistics, foremost, cognitive linguistics (Croft & Cruse 2004; Geeraerts 2006; Goldberg 1995; 2006; Lakoff & Johnson 2003; Langacker 1987; 2008), as well as emergentism (Bybee & Hopper 2001; Ellis 1998; Ellis & Larsen-Freeman 2006; Elman et al. 1996; MacWhinney 2006), constructionism (Harel & Papert 1991; Papert 2020; Piaget 2013), and complex dynamic systems theory (de Bot, Lowie & Verspoor 2007; Fogal & Verspoor 2020;
Larsen-Freeman 1997; Verspoor 2017; Verspoor, Lowie & Van Dijk 2008). These approaches are, in turn, based on decades of research in several related disciplines, including linguistic theory, psycholinguistics, cognitive and educational psychology and, more broadly, cognitive science (for a recent overview, see Ellis 2019). At the heart of all these approaches is the central notion that: “Language and its use are mutually inextricable; they determine each other” (Ellis & Larsen-Freeman 2009: 91). Language use therefore constitutes “the foundation for language learning” (Tyler & Ortega 2018: 5).

Usage-based linguistic theories place a strong emphasis on the centrality of meaning. Meaning is, of course, also a core tenet of contemporary communicative language teaching approaches. However, in usage-based language acquisition models, the centrality of meaning implies that all aspects of language, from lexis to syntax to discourse, are acquired as form-meaning pairings. These form-meaning pairings are conceptualised as constructions of various levels of complexity and abstraction: the most concrete and specific constructions are individual words and their concrete meaning in the real world, whilst more abstract ones consist of, for example, grammatical phenomena such as the present perfect or syntactic patterns such as verb argument structures, e.g., the ditransitive construction (Ellis & Ferreira-Junior 2009a: 188; see also, e.g., De Knop & Gilquin 2016; Herbst, Schmid & Faulhaber 2014; Goldberg 2006; 1995; Hoey 2005; Lewis 2009; Siepmann 2007; Sinclair 1991 on the concept of lexicogrammar).

Language is acquired as a result of exposure to these form-meaning mappings, or constructions, in “iterative usage events” (Tyler & Ortega 2018: 7; see also Barlow & Kemmer 2000) – in other words, when language users are exposed to, engage with, and produce surface-level linguistic patterns that convey specific meaning in genuine communicative situations. It is through these usage experiences that linguistic knowledge becomes entrenched in the learner’s mind (see, e.g., Blumenthal-Dramé 2012). As such, and contrary to generative, rule-based theories of language acquisition (as postulated by, e.g., Chomsky 1995; 2002), humans are not endowed with any universal or innate abstract grammar rules. Consequently, language acquisition processes are not concerned with the setting of any parameters for pre-supposed innate grammar rules, but rather language users naturally construct rules as they gradually make generalisations on the basis of the linguistic patterns they encounter over time. This, in turn, means that language structure – in the form of various kinds of constructions, e.g., words, collocations, grammar, and discourse – cannot be successfully acquired if dissociated from meaning. Hence, following a usage-based approach to language acquisition, pedagogically contrived textbook texts and contextless sentences exemplifying grammar rules are not thought to be the most successful means to learn a language.
Language learning is a process and, in this paradigm, the ability to generalise over individual language usage events and to induce meaningful categories are understood as examples of domain-general cognitive processes, i.e., abilities that are not specific or restricted to language learning (e.g., Cohen & Lefebvre 2017; Murphy 2003), but which are rather at the heart of all aspects of human learning. For language acquisition, these general cognitive mechanisms (such as memorisation, pattern finding, abstraction, induction, categorisation and schematisation) have been shown to be driven by various aspects of the input language users are exposed to; in particular, they are known to be exquisitely sensitive to frequency effects (e.g., Ellis 2002). Indeed, the degree of entrenchment of any one construction in the learner's mind is thought to be proportional to the frequency of usage (e.g., Bybee & Hopper 2001; Bybee 2007; Ellis 2002; Tomasello 2005). This means that, in a usage-inspired L2 instruction paradigm, both the quantity and the quality of language input are crucial.

## 1.5 Input and frequency

Input is, in fact, central to all theories of L2 learning and teaching and: “no model of second language acquisition does not avail itself of input in trying to explain how learners create second language grammars” (Gass 1997: 1; for more on the “input hypothesis” in SLA, see Krashen 1982; 1985). In usage-based accounts, input is understood as a wealth of information that captures both the frequencies at which various linguistic patterns occur in natural usage and the contexts in which they are most likely to (co-)occur (Bybee & Hopper 2001; Bybee 2007). Numerous psycholinguistic, corpus- and computational-linguistic studies have now demonstrated that “the acquisition of constructions is input-driven and dependent on learners’ experience with form-meaning mappings in context” (Ellis & Larsen-Freeman 2009: 92). For instance, experiments (e.g., Elio & Anderson 1981; 1984; Posner & Keele 1968; 1970) have shown that the learning of categories from prototypical exemplars is optimised when learners are exposed to language input in which the distribution of specific exemplifications of a construction are heavily skewed towards one prototypical exemplar (e.g., the verb *give* in ditransitive constructions). As they are exposed to more input, learners continually redefine the bounds of each construction category (Ellis & Larsen-Freeman 2009: 95). Corpus studies (e.g., Ellis, Römer & O'Donnell 2016; Goldberg, Casenhiser & Sethuraman 2004) have demonstrated that the natural distributions of constructions follow Zipf's law (Zipf 1935; 1949), whereby one exemplar is by far the most frequent and the frequency of the second most frequent exemplar can be expected to be approximately half the frequency of the first exemplar and so on (for a succinct explanation with clear illustrations, see Brezina 2018: 44–46). These highly frequent, semantically prototypical exemplars are thought to serve a ‘pathbreaking’ function facilitating the generalisation of a construction to more abstract instantiations (Goldberg 2006; Ninio 1999).
These effects have been demonstrated in both L1 and L2 acquisition contexts (e.g., Goldberg, Casenhiser & Sethuraman 2004; Lavi-Rotbain & Arnon 2022; Römer & Berger 2019). For instance, Ellis and Ferreira-Junior (2009a; 2009b) analysed ESL adult learners' use of three types of verb-argument constructions over a period of 32 months and found that participants' first use of each verb-argument construction was indeed with a 'pathbreaker' verb, which corresponds to the most frequent verb type of each construction in the learners' language input. Moreover, these pathbreaker verbs appear to "seed" the construction so that, over time, learners begin to use more (semantically similar) verbs as part of the process of mental abstraction of the construction. The results of these studies (see also Wulff et al. 2009) suggest that the naturally skewed distributions of construction type/token frequencies in natural language input optimises not only L1 but also L2 learning by providing one very high-frequency exemplar that is also prototypical in meaning and widely applicable in a broad range of contexts (cf. Hu & Maechtle 2021).

Thus, usage-based linguistic theories and the results of empirical studies converge to show that language learning is largely driven by frequency. That said, it is not by any means the only factor that contributes to successful language learning. Just like in all other non-linguistic learning processes, socio-emotional factors are also considered in usage-based approaches to language learning. These include surprise value, learner attention, transfer, overshadowing and blocking (see, e.g., Ellis 2002; 2006; 2008). Other important factors include the salience of a construction to comprehend or produce a particular utterance, as well as the prototypicality, generality or redundancy of a construction. Suffice to say, however, that, in naturalistic input, these aspects very often, though by no means always, correlate strongly with frequency of use. For instance, the most frequent forms are unlikely to be redundant and, as explained above, it is typically the most frequent exemplar of a construction that gives that construction its prototypical meaning (e.g., *give* in ditransitive constructions).

## 1.6 Input in lower secondary school EFL contexts

As we have seen, input is central to almost all SLA models and, in particular, to usage-based approaches, yet empirical research on the impact of input on L2 learning development remains relatively sparse (Gurzynski-Weiss et al. 2018: 292). Part of the issue is that, whilst the role of input in early L1 acquisition can be relatively easily examined by analysing the language of a young learner's main caretaker language (see, e.g., Altosaar et al. 2010; Behrens 2006; Clark & Casillas 2016; Kuhl & Meltzoff 1996), capturing the language L2 learners are exposed to is rather more complex:

> Rather than a single or limited set of caretakers, second language (L2) learners are exposed to numerous native and nonnative speakers, making it nearly impossible to accurately characterize all sources of input (Gurzynski-Weiss et al. 2018: 291).
The few studies that have attempted to do so have, however, concluded that input is equally important in L2 as in L1 acquisition (see, e.g., Moyer 2008 on phonological attainment). Whilst capturing the total language input of (adult) learners in ESL contexts is particularly tricky, in lower secondary school EFL contexts, L2 input is rather more restricted and thus easier to capture. At lower secondary school level in France, Germany and Spain extracurricular exposure to and interaction with English remains, on average, fairly limited (Berns, De Bot & Hasebrink 2007). Note, however, this is not the case everywhere (see, e.g., Henry 2014 for the case of Sweden) and that the situation is rapidly evolving. Indeed, recent surveys have shown that the proportion of teenagers in Germany who consume English-medium media is on the rise: 43% of 12- to 19-year-olds in Germany report watching YouTube videos in a language other than German – mostly English – at least once a week (Feierabend et al. 2020: 48). The percentages reported at lower secondary school level are only marginally lower: 32% for 12–13-year-olds and 39% for 14–15-year-olds (Feierabend et al. 2020: 48). We can expect similar trends in France and Spain: as teenage EFL learners’ English proficiency grows, so does their consumption of media in English and engagement in English-medium (online) communication – making it increasingly difficult to discern how much of their L2 input is classroom-based.

At the time of writing, however, formal classroom-based English input remains the dominant source of English input for most pupils at lower secondary school level in the three countries of interest (more on this in 1.7). This input consists foremost of the content of the textbook (that is: the student's coursebook, associated audio and video materials and potentially also a workbook and/or vocabulary book), teacher talk, peers' production, and, if used, any additional teaching materials. The present study was thus motivated by the combination of the centrality of input in L2 acquisition processes and the fact that a substantial proportion of that input in lower secondary school EFL contexts comes from textbooks. Indeed, although other sources of classroom-based L2 input have just been listed, large proportions of these sources are in fact directly or indirectly influenced and/or mediated by textbook content. For instance, much of teacher talk at secondary school level revolves around the textbook, its explanations, instructions, and tasks, and much of learner writing, learner-teacher and learner-learner spoken interactions are produced on the basis of these same textbook tasks, prompts and models (see, e.g., Huang 2019: 87; Thornbury 2002).

## 1.7 Textbooks in the EFL classroom

Although statistics are hard to come by (Schaer 2007: 255), there is a broad consensus on the fact that textbooks largely dominate formal L2 input in European lower secondary school EFL contexts. In fact, textbooks are almost universally “considered to be the backbone of second and foreign language teaching” (Tateyama 2019: 404; see also, e.g., Diepenbroek & Derwing 2014; Oelkers 2008). Richards (2015: 594) goes as far claiming that they largely determine teachers’ teaching practice. Across all EFL
instructional contexts, it has been deplored time and again, by language education
scholars and teacher trainers alike, that teachers are heavily dependent on textbooks
and that there is de facto no distinction between textbook and syllabus (e.g., Schaer
2007: 256; Sinclair & Renouf 1988: 145). According to Vellenga (2004: n.p.; see also,
e.g., Hyland 1994; Kim & Hall 2002), they constitute both "the centre of the
curriculum and syllabus in most [EFL] classrooms". Thornbury (2012 in a comment
response to Chong 2012: n.p.; see also Bragger & Rice 2000: 107) goes further and
claims that:

the reason that coursebooks are so often in the line of fire is that they do to a large extent dominate and determine so many aspects of a teacher's day-to-day professional life. They (more often [than] not) instantiate the curriculum, provide the texts, and – to a large extent – guide the methodology.

This view is echoed in the following observations:

Together with teaching methodologies, [textbook] materials represent the interface between teaching and learning, the point at which needs, objectives and syllabuses are made tangible for both teachers and students. They provide most of the input and language exposure that learners receive in the classroom [...]. (Hyland 2013: 391)

As Usó-Juan & Martínez-Flor (2010: 424) stress, textbooks have always tended to be
"[t]he main source of input presented in classroom settings" (see also Tono 2004: 45);
hence, this is not a new phenomenon but, in spite of much criticism of textbooks, it
is also not one that appears to be changing in any significant way.

Virtually all European lower secondary EFL classrooms are equipped with textbooks. Thus, the overwhelming dominance of the textbook as a source of L2 input that has been observed in general, global EFL contexts is likely to be also true of lower secondary school EFL education in mainland Europe. Regarding the secondary school German context specifically, Kurtz (2019: 116) speaks of the “großenteils lehrwerkorientierte Alltagspraxis des Englischunterrichts [largely textbook-oriented everyday practice of teaching English]”, especially in the “Sekundarstufe I” (Kurtz 2019: 122; see also Hermes 2009: 9), i.e., in the first five years of secondary school. Similarly, Volkmann (2010: 235) reports that:

das traditionelle Leitmedium des Unterrichts, das Lehrwerk, insbesondere das Lehrbuch (Schülerbuch), bleibt in der Phase des Spracherwerbs (also vor allem in der Sekundarstufe I) das oftmals absolut dominante Medium der Instruktion) [as the medium which has traditionally guided and organised teaching, the textbook, especially the coursebook (i.e., the pupil's book), often remains the absolutely dominant medium of instruction in the language acquisition phrase (i.e., especially at lower secondary school level)].

In some *Bundesländer*, this reliance on textbooks is, in fact, more or less directly prescribed in the curriculum. The English curriculum for *Gymnasium* in Hessen, for instance, proclaims that, at lower secondary level (*Sekundarstufe I*) the textbook is *the* "Leitmedium" (Hessisches Kultusministerium 2010: 4).
Referring to the German context more generally, Siepmann (2007: 59) points to a noticeable overlap between textbooks, syllabus and vocabulary teaching methodology when he notes that:

[i]n der Sekundarstufe I verlassen sich die Lehrer auf das Wörterverzeichnis und die Grammatik des Lehrbuchs; die ausgeprägte Einzelwortorientierung dieser Lernhilfen wird im Unterricht übernommen [at lower secondary school level, teachers rely on the textbook's vocabulary and grammar sections; the strong emphasis on individual words that these materials promote is mirrored in vocabulary teaching and explanation].

Over in Spain, Alejo González et al. (2010: 61) make very similar observations:

Spanish secondary school students meet English first and foremost in the language classroom and the coursebook that they use is likely to be their primary source of English language input.

The situation in France is particularly interesting as teachers’ perceived over-reliance on textbooks has led to calls to abandon textbooks altogether or, at the very least, to adapt and/or supplement textbook materials with ‘authentic’ texts (see 1.3). In particular, teachers in their post-studies qualification stage are often told by teacher trainers and assessors to avoid relying on a textbook in their observed (and assessed) classes. This backlash has led many French EFL teachers to resorting to a mix-and-match approach – combining texts and activities from several textbooks and additional resources, rather than relying on a single textbook series (personal communication with practising teachers, see also Various users of neoprofs.org 2016; Séré & Bassy 2010: 10–11). Nonetheless, even when surveyed by the Ministry of National Education, French EFL teachers report that, at *collège* level [lower secondary school, see Table 3], textbooks are “*indispensable*” (Leroy 2012: 62).

The palpable tension concerning the use of textbooks in French EFL classrooms is, in fact, symptomatic of a far more universal love-hate relationship with textbooks in ELT. Indeed, in spite of the undeniable popularity of EFL textbooks, as demonstrated by their widespread use in foreign language classrooms across the world and the great range of publications on offer, detractors have regularly deplored the “superficial and reductionist” content of textbooks, that impose “uniformity of syllabus and approach” and remove “initiative and power from teachers” (Tomlinson 2001: 67). Following this line of thought, Prabhu (1989) argues that textbooks rob teachers of the freedom to freely order, use and localise materials.

Another important factor to consider is that most EFL textbook publishing houses are commercial, for-profit businesses. Some have therefore claimed that textbook publishers do not always have learners’ best interests at heart since, at the end of the day, learners are rarely involved in textbook selection processes (in fact, it is not rare for teachers to be entirely excluded from textbook selection processes, too, see, e.g., Friederici 2019; Stein et al. 2001: 5–6; Stranks 2013: 338). It has been argued that privately outsourcing such a crucial aspect of EFL education has the potential to stall
the implementation of recent research findings in applied linguistics, second language acquisition and other relevant disciplines. Some claim that “the economic imperative” incites publishers to “clone previously best-selling coursebooks rather than risk investment in more principled innovations” (Tomlinson 2013b: 541; see also the conclusions of Burton 2019 whose analysis of the “canon of pedagogical grammar” in ELT textbooks combines textbook content analysis and interviews with textbook authors, editors and publishers). The situation can be summarised as follows:

Publishers obviously aim to produce excellent books which will satisfy the wants and needs of their users but their need to maximize profits makes them cautious and conservative and any compromise with authors tends still to be biased towards perceived market needs rather than towards the actual needs and wants of learners (Tomlinson 2013b: 3).

This is not to say that attempts at innovation have not been made – on the contrary. For example, the ‘lexical approach’ (Lewis 1993; 1997; 2009), that challenges the all-empowering centrality of grammar in the L2 syllabus, inspired the design of a number of commercially published textbooks (e.g., Dellar & Hocking *Innovations*, 2000; Dellar & Walkley, *Outcomes*, 2011). These emphasised the importance of conceptualising language as ‘grammaticalised lexis’ as opposed to the customary ‘lexicalised grammar’ approach (Lewis 1993: 34) using corpus-informed texts and activities. Presumably these were not great commercial successes, however, because a brief tour of the tables of contents of today’s most popular EFL textbooks clearly shows that these continue to treat grammar and vocabulary as two distinct areas of language teaching and learning (see also Tan 2003). Again, it is easy to see how school textbook publishers would be placing themselves at a competitive disadvantage if they were the first to remove what has come to be an expected feature of foreign language textbooks and has, so far, proved to be an attractive selling point.

The constraints associated with the commercial production of ELT materials have been extensively discussed in, among others, Bell & Gower (2011), Richards (2015) and Gray (2010). Although these publications tend to focus on the global ESL/EFL textbook market, most often targeted at adult learners, continental European publishers producing school textbooks for their respective domestic markets likely face many of the same constraints.

An additional constraint, and one that may be more specific to the European textbook market, is that European foreign language curricula and syllabi are now largely aligned with the CEFR. Indeed, the CEFR has established itself as an unavoidable pedagogical framework for language learning and teaching in European schools and, as such, has had a major influence on textbook and task design (Hallet & Legutke 2013: 8) in spite of much criticism of the framework (for the German context, see, e.g., Bausch 2005; Vogt 2011).
Given the widespread criticism of textbooks for a multitude of reasons, we may ask: why *are* textbooks nonetheless so ubiquitous in ELT and even considered “indispensable” (Leroy 2012: 62) by many secondary school EFL teachers? As any practising teacher can attest, textbooks are, first and foremost, a much-needed timesaver when teachers’ timetables are packed and classes full (see, e.g., Nordlund 2016: 48). Recognising a genuine need to reduce teachers’ preparation load, textbook publishers have responded by adapting their business models and are now marketing all-encompassing “multidimensional packages” (Dat 2013: 409) which go well beyond what was traditionally understood as a textbook. For each textbook within a textbook series, these packages now frequently include, in addition to the pupil’s coursebook, an activity workbook and a teachers’ manual with often very detailed lesson plans, step-by-step instructions, extra photocopiable worksheets, answer sheets, as well as optional related games, quizzes, and assessments, vocabulary apps, audio recordings, videos, graded readers, etc. (Dat 2013: 410–411). Given the wealth – and, it is worth highlighting, the often high quality – of these materials, it is easy to see how, in particular inexperienced, teachers can quickly come to rely on them so much.

In general, the textbook (package) is perceived as a trustworthy authority (e.g., Abello-Contesse & López-Jiménez 2010; Brown 2014; Chien & Young 2007; Ghosn 2013). There is often a sense that, if it is followed to the letter, teachers can be reassured that their lessons will cover all aspects of the curriculum and syllabus (Nordlund 2016: 48). Textbooks therefore contribute to standardising learning outcomes (Anton 2017: 13). In many cases, textbooks also act as a mark of credibility vis-à-vis ever-more demanding parents. Furthermore, textbooks are frequently seen – by learners, teachers and parents alike – as an ideal way to present contents in a well-structured and systematically organised order, following tried-and-tested progressions (Burton 2019; 2020; Möller 2016). This leads to:

a circle (whether vicious or virtuous), whereby publishers provide their customers with the kind of teaching materials that they are asking for, and their customers continue to ask for the same kinds of teaching materials as they feel that what they have seen before represents the norms they should be following (Burton 2019: 220–221).

The fact that these norms and progressions may be the product of decades of innovation stagnation rather than the conclusion of any empirical studies on learners’ development of linguistic competence in instructional EFL settings is usually overlooked. On the contrary, textbooks are often perceived as “Innovationsträger [drivers of innovation]” that bring pedagogical research findings and new teaching methods to the foreign language classroom (Anton 2017: 14).

Given the rapid growth in technology-based ELT and, more generally, computer-assisted language learning (CALL; see, e.g., Chapelle 2010), it may seem rather inconceivable that, in the late 2010s and early 2020s, secondary school learners’ main source of formal English input still comes in the form of book publications (Bezemer
& Kress 2016: 477). Vague claims and slogans such as “*Die Perspektive des Schulbuchs ist digital* [The future of the textbook is digital]” (Landesregierung Nordrhein-Westfalen 2016: 8, 25) found in North-Rhine Westphalia’s *Leitbild 2020 für Bildung in Zeiten der Digitalisierung* [Mission statement for 2020 for education in the day and age of digitalisation] are, indeed, frequently heard. Yet, to date, the vast majority of so-called “digital textbooks” and their accompanying e-materials are essentially replicas of the same textbooks, graded readers, grammar books and flashcards that publishers still successfully sell in paper form. Hence, although all major school textbook publishers now promote various digital textbook packages (Kurtz 2019: 119), for now, these digital textbooks offer little more than digitised versions of their paper counterparts. They represent little to no change in terms of content or teaching methodologies (see, e.g., Gehring 2013; Richards 2015: 594; Stranks 2013: 348–349; Schildhauer, Schulte & Zehne 2020: 30–31). The obvious lack of suitable digital materials (as well as, crucially, teacher training in using existing digital resources and, in many cases, the necessary equipment and infrastructure) made headlines during the (partial) school closures triggered by the COVID-19 pandemic (see, e.g., Blume 2020; Fominykh et al. 2021; Kerres 2020; Starkey et al. 2021; van de Werfhorst, Kessenich & Geven 2020). Whilst the urgency of the epidemiological situation is likely to have accelerated both the development and the acceptance of new digital teaching materials compatible with online, on-site and hybrid instructional settings, genuine advances in commercial materials development can nevertheless be expected to remain slow. Indeed, academic research has been churning out innovative, evidence-based ideas for new digital L2 teaching materials for the better part of a decade (see, e.g., Biebighäuser, Zibelius & Schmidt 2012; Meurers et al. 2010; 2019); however, few of these ideas have been translated into any of the best-selling secondary school EFL textbook series examined as part of the present study. It would thus appear that textbook publishers face the same constraints as ever. In the textbook industry, innovation remains a commercial risk.

As this section has shown, Vellenga’s (2004: n.p.) statement that “textbooks remain the most important tools and resources in the EFL classroom” still rings true today – in spite of their many shortcomings (see also Möller 2016). In addition, it has concluded that textbooks continue to play a particularly important role at lower secondary school level – accounting for a substantial, if not the largest, proportion of L2 input EFL learners are exposed to. Gaining a comprehensive understanding of the language that modern secondary school EFL textbooks present to learners is therefore of high pedagogical value. This is precisely what the present thesis sets out to achieve.

The approach adopted to do so is corpus-based. In other words, the totality of texts from a representative sample of EFL textbooks used at lower secondary school level in France, Germany and Spain (see Table 5) is analysed as a “learners’ L2 [input] corpus” (Gabrielatos 1994: 13; see also Meunier & Gouverneur 2007: 122). Thus,
rather than following a page-by-page textbook analysis approach, the language of this
corpus of “Textbook English” (see 3.3.1 for details of its composition) is examined as
a variety of English, much like Academic English, Australian English or Aviation
English.

1.8 Corpus linguistics and foreign language education

The present corpus-based textbook analysis study follows in the footsteps of a now
decade-long tradition of “pedagogy-driven corpus-based research” (Gabrielatos 2006:
1). Corpus-based methodologies rely on the exploration of language corpora,
principled computerised collections of real-life, authentic texts, to investigate patterns
of language use. Corpus linguistics is characterised by its empirical basis, analysing
(usually large) collections of texts using automatic and interactive data retrieval
techniques, and by its application of mixed quantitative and qualitative analytical
methods. Drawing on corpus data without (too many) assumptions allows linguists
to observe language features, e.g., lexico-grammatical patterns and other phenomena,
which have not necessarily been previously explored or described (Hunston 2002: 1).
For example, analyses of corpora of spoken British English revealed highly frequent
lexico-grammatical features in spoken English which had previously not been
considered in traditional grammars (see, e.g., Carter & McCarthy 1995; McCarthy &
Carter 1995; Carter, Hughes & McCarthy 1998; Hughes 2010; McCarthy 1998).

As a discipline, corpus linguistics has, from the outset, positioned itself as a decisively
applied subdiscipline of linguistics. Pedagogical applications have been at the heart
of many strands of corpus-linguistic research and corpus methods<fnref n="9" /> are now widely
used in numerous areas of applied linguistics relevant to second language acquisition
and foreign language education. In particular, corpus-linguistic methods have now
become the norm in (learner) lexicography (see, e.g., Granger 2018; Rundell 2008;
Runte 2015) and, since the 1990s, have had a major impact on the development of
reference and learner grammars of English (e.g., Biber et al. 1999; Conrad, Biber &
Leech 2011 for English; see also Siepmann 2018a; 2019; Siepmann & Bürgel 2022 for
a corpus-based learner grammar of French). For instance, the second edition of the
*Longman Grammar of Spoken and Written English* (Biber et al. 1999) relied
exclusively on empirical data drawn from corpus analyses (Conrad 2000: 548–549).
Moreover, corpora of learner language, both written and spoken, have been used in
contrastive studies comparing learner language to native and/or non-native expert
language use to investigate the influence of learners’ L1s on their L2 productions (e.g.,
Bruyn & Paquot 2021; Granger, Hung & Petch-Tyson 2002; Tracy-Ventura & Paquot
2020), as well as in a host of natural language processing (NLP) applications, e.g., to
automatically score and mark learner texts, perform proficiency level classification,

<footnote n="9">⁹ For more on the debate of corpus linguistics as a discipline vs. a methodological framework, see Stefanowitsch (2020: 21–60) and Taylor (2008).</footnote>
error detection and/or correction (e.g., Ballier, Díaz Negrillo & Thompson 2013; Leacock et al. 2010; Meurers 2015; Reder, Harris & Setzler 2003).

According to Granger (2004: 136), the main fields of pedagogical application of corpus data are classroom methodology and materials and syllabus design. However, Granger (2004: 136) adds that “with the exception of ELT dictionaries, the number of concrete corpus-informed achievements is not proportional to the number of publications advocating the use of corpora to inform pedagogical practice”. Recent studies appear to confirm that this statement is, unfortunately, very much still valid today (see, e.g., Callies 2019; Chambers 2019; Jablonkai & Csomay 2022).

Concerning the impact of corpus data on pedagogical methods, most research has so far focused on data-driven learning. However, in spite of the wealth of publications on data-driven learning going back to the work of Tim Johns from the 1980s onwards (e.g., Johns 1986; 1993; 2002; 2014) and a myriad of studies pointing to its effectiveness in a wide range of teaching contexts (summarised in two recent meta-analyses Boulton & Cobb 2017; Lee, Warschauer & Lee 2019), the direct use of corpora in the foreign language classroom has yet to become more than an exception to the norm (Barbieri & Eckhardt 2007: 320; see also Callies 2019; Leńko-Szymańska & Boulton 2015; Leńko-Szymańska 2017; Mukherjee 2004).

As for the application of corpus data in materials and syllabus design, corpus linguists have long sung the merits of incorporating corpus-based findings in L2 materials in a way that will inevitably require some modifications to traditional foreign language syllabi (e.g., Biber & Reppen 2002a; Conrad 2000; Frazier 2003; Harwood 2005; Holmes 1988; Granger 2004; McCarthy & Carter 1995; Nelson 2022; Timmis 2013); yet, in spite of the growing availability of freely accessible corpora and corpus research findings, very few EFL textbooks are advertised as corpus-informed, let alone corpus-based. In the rare cases where corpora do inform EFL textbook design, it tends to be in the context of English for Special Purposes (ESP) and English for Academic Purposes (EAP) textbooks (Meunier & Gouverneur 2009: 180–181). General EFL textbooks, by contrast, appear to remain largely unaffected by such moves (for a notable exception see the *Touchstone* series by McCarthy et al. 2006).

When Prowse asked ELT materials designers how they approached textbook writing back in 1988, the authors stressed the creative nature of the writing process. Prowse (Prowse 1998: 137) concluded that most textbook authors:

* appear to rely heavily on their own intuitions viewing textbook writing in the same way as writing fiction, while at the same time emphasizing the constraints of the syllabus. The unstated assumption is that the syllabus precedes the creation.

A few decades later, Burton (2012) conducted a case study survey of fifteen EFL coursebook authors, which revealed that authors still largely relied on their intuition.
Accessibility issues, lack of relevant skills and knowledge, and time constraints were all cited as reasons for their lack of use of corpora designing ELT materials. Given the wealth of English-language corpora and accessible, user-friendly tools that became available over the past few decades, this lack of innovation is regrettable. Indeed, as corpus-based English grammars such as the *Longman Grammar of Spoken and Written English* (Biber et al. 1999; see also Biber et al. 2021 for a more up-to-date corpus-based English learner grammar) have since shown:

> Unfortunately, decisions about the sequencing of material, typical contexts, and natural discourse are not served as well by intuition and anecdotal evidence as judgments of accuracy are (Biber & Conrad 2001: 1).

Analysing in-depth interviews with four ELT editors employed by Cambridge University Press (CUP), Curry et al. (in press) yielded more recent insights into what textbook editors currently perceive as the advantages and limitations of corpus linguistics for ELT materials development. It transpired that the perceived limitations are largely traceable to limited knowledge about existing corpora (including what kind of corpus metadata are available and how they can be exploited) and corpus tools.

The conclusions of this most recent survey are particularly sobering considering that CUP likely represents a notable exception in the ELT publishing world; indeed, it has a long tradition of collecting and processing data for the (co-)development of language corpora. Most notably, it has been instrumental in the development of the Cambridge Learner Corpus, which is used by CUP authors to target common learner errors in ELT publications, including textbooks. In this respect, it also constitutes an exception to what Granger (2015: 494) describes as learner corpora's “more nominal than real” impact on textbooks.

If corpora and the insights of corpus-linguistics studies have yet to be taken on board by EFL textbook authors, editors and publishers, it is nonetheless possible to examine and evaluate the language of textbooks using corpus-linguistic methods (see also Nelson 2022). This is what the present thesis sets out to do. As will be shown in the following literature review chapter, it is not, by any means, the first study to attempt to do so. The organisation of this state-of-the-art chapter, as well as of the remaining chapters of this thesis is spelt out in the following section.

## 1.9 Outline of the thesis

Having explained the background to and motivation behind the present study, the following literature review chapter (Chapter 2) provides an overview of state-of-the-art research on the language of school EFL textbooks. It is divided into two parts. Part 1 is a methodological review in which the various methods employed so far to analyse, describe and evaluate Textbook English are explained and illustrated with
selected studies. Part 2 summarises the results of existing studies on various aspects of Textbook English, including lexical, grammatical and pragmatical aspects. Based on the methodological limitations and the gaps identified in the existing literature, Chapter 3 elaborates the specific research questions addressed in the present study. These research questions informed the decision-making processes involved in the compilation of the Textbook English Corpus (TEC) and the selection/compilation of three target learner language reference corpora. These processes and their motivations are explained in the remaining sections of Chapter 3.

The research questions are then tackled at two levels. First, Chapters 4 and 5 examine Textbook English at the micro-level – focusing on two individual lexico-grammatical features in two case-study chapters. Chapter 4 analyses a grammatical feature explicitly taught in the grammar sections of the examined textbooks – the progressive, whilst the following chapter turns to the more implicit use of specific lexico-grammatical patterns involving the high-frequency verb MAKE. Chapters 6 and 7, by contrast, explore Textbook English at the macro-level, using multi-variable dimension-reduction statistical methods to gain a more comprehensive understanding of the linguistic nature of Textbook English on multiple dimensions of variation.

Chapters 4 to 7 each rely on different corpus-linguistic methods and therefore each of these four results chapters begins with its own methods section. Parts of Chapter 4 are essentially an extended conceptual replication of Römer’s (2005: Ch. 5–6) extensive analysis of the representations of the progressive in the dialogues of EFL textbooks used in German secondary schools with some methodological refinements. Section 4.2.3 explains the underlying principles of the family of collostructional analysis methods (Stefanowitsch & Gries 2003; Gries & Stefanowitsch 2004a; Gries 2019a) as these are applied in both Chapters 4 and 5. Chapter 6 describes Textbook English using Biber’s (1988) multi-dimensional model of General Spoken and Written English. Chapter 7 features the most extensive methods section as it proposes a range of modifications to the well-established multi-feature/dimensional analysis framework (Biber 1988; 1995; Berber Sardinha & Biber 2014; Berber Sardinha & Veirano Pinto 2019) based on limitations of the method observed in Chapter 6.

Using this revised multi-feature/dimensional analysis (MDA) framework, Chapter 7 presents the results of two multi-dimensional models of Textbook English which, across several major dimensions of linguistic variation, explain, on the one hand, the various sources of linguistic variation within EFL textbooks and, on the other, the way in which Textbook English is both, in some respects, similar to and, in others, different from the kind of English that EFL learners are likely to encounter outside the classroom. Thus, the models contribute to a much better understanding of the linguistic specificities of Textbook English which, in turn, has implications for teachers, textbook authors, editors, publishers and policy-makers. For instance, with
a greater awareness of how far-removed textbook dialogues are from natural conversation, teachers may want to supplement textbook materials with other teaching materials that better represent real-life conversation.

Chapter 8 summarises and brings together the results of the two case studies and the insights from the new multi-feature and multi-dimensional models of Textbook English presented in Chapter 7. Both methodological and pedagogical implications are discussed. Lexico-grammatical aspects of Textbook English that substantially diverge from the target reference corpora are highlighted. Suggestions are made as to how teachers, textbook authors and editors may improve unnatural-sounding pedagogical texts. Suggestions are also made for triangulating the results with learner corpus data to investigate the impact of Textbook English on EFL learners' productive competences. Some of the corpus-linguistic methods applied in the present study may also be of interest to textbook authors, editors, publishers, and representatives of education authorities interested in evaluating and/or comparing the suitability and naturalness of pedagogical texts. To this end, and in the interest of Open Science (see 3.2.2), the data and code for all the analyses carried out as part of this project have been published in a public repository on GitHub (https://github.com/elenlefoll/TextbookEnglish). They are also accessible from the Online Appendix hosted on https://elenlefoll.github.io/TextbookEnglish.
## 2 Literature review

> *Tradition, even if it is most venerable,
> cannot serve as a substitute for research.*

❖ Dieter Mindt (1997a: 41)

Having established that both the frequency and quality of input is fundamental to L2 acquisition and that, at least in the context of European secondary schools, textbooks account for a large proportion of learners’ language input, the following question arises: Are secondary school textbooks providing the kind of language input that will promote ‘authentic’ language acquisition, or, to quote the Standing Conference of the German Ministers of Education (Kultusministerkonferenz 2003: 9) “the correct use of typical and frequent linguistic elements”? In an attempt to shed light on this question, the present chapter will present previous research on the language of EFL textbooks. Only where methodological innovations or specific fields have been left out in English for General Purposes (EGP) or secondary school EFL textbook studies, will the occasional reference to textbooks of other foreign languages, or textbooks for other levels and learning contexts be made.

Textbooks have long been a cherished object of study in a wide range of disciplines applying an equally diverse array of methods. As “social-cultural-political artefact[s]” (Singapore Wala 2013: 120), foreign language textbooks may also be considered as “sources not only of grammar, lexis, and activities for language practice, but, like Levi’s jeans and Coca Cola, commodities which are imbued with cultural promise” (Gray 2000: 274). As such, it is quite natural that the broad spectrum of EFL textbook studies should include fields of research as disparate as the pragmatics of politeness in German EFL textbooks (Limberg 2016), semiotic approaches to the representation of culture in Hungarian EFL textbooks (Weninger & Kiss 2013), and the evaluation of interactional metadiscourse in Iranian EFL textbooks (Alemi & Isavi 2012), using an equally broad range of different methods. Though research on EFL textbooks extends well beyond “the linguistic nature of their content” (Littlejohn 2011: 182), the present study focuses exclusively on the language of textbooks – as opposed to the pedagogical reasoning behind the textbooks’ tasks and activities and their effectiveness (see, e.g., Harwood 2005; Jacobs & Ball 1996; Ranalli 2003), its layout or the nature of content topics chosen by the textbook authors (see, e.g., recent special issue of *Language, Culture and Curriculum*; Canale 2021; also Siegel 2014), or its adherence and fulfilment of specific educational standards (e.g., Cools & Sercu 2006 on the extent to which the tasks and topics of two German as a Foreign Language textbooks are aligned with the CEFR) – hence the studies reviewed in the present chapter all focus on the linguistic content of EFL textbooks, hereafter referred to as ‘Textbook English’.
The present literature review does not claim to cover the full breadth of past and
current research on the language of EFL textbooks. In fact, to the author's best
knowledge, no systematic review of Textbook English studies has been attempted so
far. This is likely due to the incredibly diverse range of methods and linguistic foci
that characterise this field of study, as well as the many different types of English
textbooks that cater for different instructional settings, proficiency levels and regional
markets and are therefore not readily comparable. The most comprehensive overview
of English textbook research to date can be found in Meunier & Gouverneur (2009:
183–184). A total of 27 studies, spanning from 1990 to 2009, are summarised in a
tabular format. The overview not only covers the linguistic content of textbooks, e.g.,
its “authenticity”, grammar and vocabulary, but includes a few studies on non-
linguistic aspects of textbook research, e.g., task design.

Following a similar approach, all the relevant studies surveyed as part of this
literature review are summarised in a table that can found in the *Online Appendix 2.1*.
It presents the results of a non-exhaustive survey of Textbook English
studies published over the past four decades, summarising some of the key information
on each study, including its main language focus, methodological approach,
information on the textbooks investigated, and, if applicable, on any reference corpora
used. Empty cells represent fields that are either not applicable to this particular
study or for which no information could be found. Intended as a dynamic resource,
this interactive, searchable, and filterable table currently lists over 80 studies on the
language content of English L2 textbooks, thereby demonstrating the breadth of
Textbook English studies published to date.

In light of the sheer number of publications on the subject, the present chapter can
only aim to provide key insights from a selection of studies. To this end, this chapter
is subdivided into two main parts. Part one (2.1) focuses on the methodologies applied
from the 1980s to the present day with the aim of investigating the authenticity
and/or pedagogical relevance of various features of Textbook English. Summaries of
individual studies serve to exemplify the methodological approaches described. In this
first part, the results of studies are only presented to illustrate the advantages and
limitations of each method. Part two (2.2) then reports on key results from a range
of relevant Textbook English studies, including the ones outlined in the
methodological part of the chapter (2.1). Since some aspects of Textbook English
have been at the heart of more than one study, this second half is organised in sections
that roughly correspond to the different types of linguistic features examined in these
studies (tense, aspect, lexis, etc.), rather than by chronological order. The chapter
concludes with a list of implications for the present study that concern both the choice
of data and methods and the language focus of the ensuing analyses (2.3).
## 2.1 Part One: Methodological review

### 2.1.1 Intra-textbook approaches

The studies outlined in the following sections focus exclusively on describing Textbook English without relying on any form of comparison with other sources of English. Such 'intra-textbook' approaches are illustrated in the following sections with, first, check-list approaches (2.1.1.1), second, largely qualitative page-by-page surveying methods (2.1.1.2), and third, corpus-based intra-textbook methods that rely more on quantitative analyses (2.1.1.3).

#### 2.1.1.1 Checklist approach to textbook evaluation

Perhaps the most common approach to evaluating textbooks, and one that will be familiar to many practising teachers, consists in choosing, adapting or developing and then applying checklist-based evaluation frameworks. Typical EFL textbook checklists can feature anything from a dozen (e.g., Garinger 2002) to over a hundred criteria (e.g., Tomlinson et al. 2001). They usually resort to *ad hoc* considerations of the pedagogical and linguistic content of the textbooks, rather than apply any form of empirical measures. Thus, practitioners are expected to be able to answer questions such as: “Do the exercises and activities in the textbook promote learners’ language development?” (Garinger 2002: 2) or “Are the grammar rules presented in a logical manner and in increasing order of difficulty?” (Miekley 2005: n.p.) without resorting to any concrete norms, standards, methodologies or tools.

It goes without saying that attempting to construct a checklist designed to objectively evaluate foreign language textbooks across all dimensions constitutes a truly monumental task. By way of illustration, Tomlinson et al. (2001) devised a set of 133 criteria and used them to each, independently, evaluate eight adult ELF textbooks. The results of their analysis are derived from the mean scores of the four researchers' criteria scores, yet they concede that “the same review, conducted by a different team of reviewers, would almost certainly have produced a different set of results” (Tomlinson et al. 2001: 82). Thus, if checklists are completed without any comparison benchmarks, the results of such checklist-based evaluations risk being largely based on subjective judgement. An advantage of this method, however, is that checklists can easily be adapted to specific teaching contexts. However, this very advantage also entails a risk: rarely are these custom-made checklists thoroughly evaluated in terms of their reliability and validity (Mukundan 2010: 271). For a comprehensive review of checklist-based evaluation frameworks for EFL textbooks, see Mukundan & Ahour (2010).
2.1.1.2 Page-by-page intra-textbook analysis

Before the advent of computer-readable corpora, manual page-by-page surveying of
publications was the only way to conduct textbook language studies. In fact, for some
types of investigations, this approach is still popular (e.g., Cullen & Kuo 2007; Timmis
2003; Vellenga 2004). By way of illustration, the following section considers the
manual intra-textbook methodology applied in Vellenga's (2004) study on pragmatic
information featured in EFL grammar textbooks and integrated skills textbooks.

The study is largely qualitative in nature, though Vellenga (2004) provides basic
quantitative analysis gleaned from manually counting the number of pages containing
pragmatic information (defined as “any information related to culture, context,
illocutionary force, politeness, appropriacy and/or register”, Vellenga 2004: n. p.) as
compared to the total number of pages in each textbook. This page-by-page counting
approach is not without its problems and, indeed, Vellenga warns that the resulting
“percentages of pages featuring pragmatic information” are somewhat misleading,
since, in most cases, pragmatic information only comes in the form of one or two
sentences on any one page, thus the page-counting method is prone to producing
inflated percentages. In each of the textbooks investigated, Vellenga also counts the
number of explicit mentions and metapragmatic descriptions of 21 different speech
acts, such as requests, apologies and complaints. Furthermore, she identifies instances
of metalanguage in the textbooks<fnref n="10" /> and codes them according to four types of
functions: description, instruction, introduction, and task-related. Using this data,
Vellenga proceeds with descriptive analyses of the types of sentences used in the
metalanguage - imperative, declarative and interrogative - and makes *ad hoc*
observations about the use of pronouns in metalanguage.

In addition, Vellenga conducted telephone interviews with four experienced EFL/ESL
teachers to inquire whether they thought that the textbooks presented issues of
politeness and contextual language use in an appropriate manner, and to ask whether
the interviewees supplemented textbook materials with additional pragmatic
information. Such methodological triangulation can be a very meaningful addition to
such an intra-textbook page-by-page analysis but nevertheless bears the same risks
observed with the checklist method in terms of poor reliability and validity.

2.1.1.3 Corpus-based intra-textbook analysis

One of the conclusions of Vellenga's (2004) study is that some of the worrying
observations in the representations of pragmatic information in EFL textbooks would
merit further exploration in a larger study. This could be achieved by replicating the

<footnote n="10">¹⁰ Note that, here, Vellenga only considered texts “used to preface activities and explain grammatical points” for the analysis of metalanguage, since, as she points out, “[t]he entire contents of a textbook, by its very nature, can be considered metalinguistic” (2004: n. p.).</footnote>
analysis on a large corpus of EFL textbooks using (partially) automated corpus queries and other corpus-linguistic methods. However, it is questionable as to whether a larger, more quantitative, intra-textbook study would yield results of any greater linguistic or pedagogical significance.

This is illustrated with an example from a corpus-based intra-textbook study assessing the distribution patterns of articles and of their colligation patterns (e.g., *a* + singular count nouns, *the* + ordinal) in a corpus of Malaysian ESL textbooks (Mukundan, Leong Chiew Har & Nimehchisalem 2012). Information on the frequency and distribution of articles and their colligation patterns was extracted automatically from the corpus data. The authors concluded that, in the five textbooks analysed, the article ‘*an*’ is considerably less frequent than the articles ‘*the*’ and ‘*a*’ (see first columns of Table 1). The article subsequently claims that teachers should therefore “create appropriate teaching materials to expose the learners more to the article ‘*an*’” (Mukundan, Leong Chiew Har & Nimehchisalem 2012: 67). However, a quick query of the British National Corpus 1994 (hereafter BNC1994; Burnard 2007) suffices to show that the proportional article frequencies observed in these Malaysian textbooks are, in fact, very comparable to the proportions of article frequencies found in a balanced corpus of naturally occurring English (see Table 1).

<table><caption>Table 1: Distribution of the articles *a*, *an* and *the* in the five Malaysian textbooks examined by Mukundan et al. 2012 (as reported in Table 1, p. 69) and in the BNC1994 (as calculated by Sketch Engine on 13.10.2018) in raw numbers and as a % of articles</caption><thead><tr><th></th><th>a (n)</th><th>a (%)</th><th>an (n)</th><th>an (%)</th><th>the (n)</th><th>the (%)</th></tr></thead><tbody><tr><td>Textbook 1</td><td>1,097</td><td>25.88%</td><td>141</td><td>3.33%</td><td>3,001</td><td>70.79%</td></tr><tr><td>Textbook 2</td><td>1,271</td><td>32.61%</td><td>130</td><td>3.34%</td><td>2,496</td><td>64.05%</td></tr><tr><td>Textbook 3</td><td>1,630</td><td>31.95%</td><td>162</td><td>3.18%</td><td>3,309</td><td>64.87%</td></tr><tr><td>Textbook 4</td><td>1,894</td><td>27.90%</td><td>209</td><td>3.08%</td><td>4,685</td><td>69.02%</td></tr><tr><td>Textbook 5</td><td>1,762</td><td>25.92%</td><td>256</td><td>3.77%</td><td>4,779</td><td>70.31%</td></tr><tr><td>Textbook series (1-5)</td><td>7,654</td><td>28.54%</td><td>898</td><td>3.35%</td><td>18,270</td><td>68.12%</td></tr><tr><td>BNC1994</td><td>2,136,923</td><td>25.31%</td><td>333,044</td><td>3.94%</td><td>5,973,437</td><td>70.75%</td></tr></tbody></table>

There may well be pedagogical arguments as to why including more explicit teaching material on the article ‘*an*’ may be beneficial but, given that this is far from the case in real-life English usage, textbook authors can hardly be expected to feature all three articles in equal proportions.

Another interesting form of intra-textbook analysis worth mentioning is found in Moreno (2003), in which the accounts of causal metatext (lexico-grammatical features that explicitly signal causal relations) featured in eleven English for Academic
Purposes (EAP) textbooks are compared to the actual expression of causal coherence relations in authentic essays, or extracts of essays, featured in the same textbooks. The author claims to have only included “authentic essays” in these comparisons, but the report does not explain how such an “authentic status” was determined. This is problematic given that it is common for texts featured in textbooks to be presented as “authentic”, even if they have been purposefully written as pedagogical material. At the very least, these texts can be expected to have been purposefully chosen to illustrate the linguistic features explained in these textbooks so that their authentic representativeness of general, here Academic, English can be called into question.

### 2.1.2 Comparative approaches

The previous section explored non-comparative methods to describe Textbook English and, citing Mukundan et al.’s (2012) investigation of articles in Malaysian EFL textbooks and Moreno’s (2003) analysis of causal coherence relations in EAP textbooks as examples, pointed to the risks of making pedagogically-motivated evaluations from analyses of textbook language alone. The methods described hereafter involve comparing aspects of the language presented in EFL textbooks with real-life, naturally occurring language data, usually in the form of a reference corpus (2.1.2.3), but also of corpus-based frequency lists (2.1.2.1), or of semi-staged re-enactments of the situations portrayed in the textbook dialogues (2.1.2.5). In particular, the methodologies of two pioneers in the field, Magnus Ljung and Dieter Mindt, will be detailed.

In the mid-1980s and early 1990s, Ljung (e.g., 1990; 1991) conducted an early corpus-driven analysis of the English vocabulary taught in upper secondary EFL classes in Sweden. As part of a large project, his team collected 56 Swedish TEFL publications (designed for the final three years of secondary education) and converted their entire content to machine-readable text. The COBUILD corpus (the main and reserve corpora totalling some 18 million words of mostly written texts; Sinclair et al. 1990) was chosen as a reference corpus, as – at the time – a large collection of contemporary mostly British non-specialist texts. Both corpora were lemmatised and Ljung (1991) subsequently extracted the most frequent 1,000 words in both the pedagogic material corpus and the COBUILD corpus in order to investigate the nature of words unique to either top-frequency word lists, as well as the differences in frequencies between shared words.

Within the confines of this top 1,000-word frequency band, the two corpora shared 796 words. Ljung (1991) analysed the nature of words unique to the TEFL high-frequency list and concluded that the majority of nouns and verbs denote physical objects, processes and human actions, whilst the adjectives express “either emotional judgement (*terrible, wonderful*), physical characteristics (*soft, bright*), or feelings (*angry, glad*)”. In contrast, a large proportion of the nouns exclusively found on the
COBUILD high-frequency list denote abstract concepts (*argument*, *decision*, *difficulty*), or can be classified as terms from the semantic fields of society or politics (*community*, *council*, *campaign*, *tax*). The high-frequency verbs are predominately used to evaluate human behaviour (*achieve*, *argue*). Moreover, the majority of the adjectives found in the COBUILD list do not denote physical characteristics (*international*, *basic*, *central*).

As for the observed differences in the frequencies of the shared words, in effect, these
do little else but reveal that the reference corpus used in these early comparative
corpus-based Textbook English studies features mostly elaborate, professionally
written and published written texts often on topics quite far removed from those of
school textbooks, whereas the pedagogical material appears to have a strong focus on
spoken or spoken-like texts. For instance, Ljung (1991) notes that contractions are
far more frequent in the TEFL corpus than in the COBUILD. Similarly, he finds that
first-, second- and third-person pronouns are more frequent in the TEFL material.
Though certainly no mean feat in the 1990s, these results essentially point to the
fundamental necessity of drawing on an appropriate reference corpus for the results
of such comparative corpus-based textbook analyses to be in any way meaningful.

2.1.2.1 Word-frequency lists approaches

The decades following Ljung’s pioneering work, analyses of the vocabulary of EFL
textbooks have continued to rely on comparisons of the words found in the EFL
publications to corpus-derived frequency word lists. The following section describes
more recent and, given modern computing power, less work-intensive, corpus-based
methods involving the computation of frequency lists and rates of word repetition in
EFL textbooks. The studies chosen to illustrate this approach deal with phrasal verbs
(Zarifi & Mukundan 2012) and prepositions (Mukundan & Roslim 2009); however,
the method is applicable to any other kind of lexical unit.

Zarifi & Mukundan's (2012) study on phrasal verbs examines a corpus of the spoken
sections of five Malaysian secondary school ESL textbooks. First, all occurrences of
19 particles were located using the wordlist function of the software WordSmith
(Scott 2011). The researchers then manually identified and tagged the occurrences of
phrasal verbs (as opposed to, for example, prepositional uses of these particles). This
procedure led to the identification of 108 instances of a total of 66 different *verb +
particle* constructions in the spoken textbook corpus. These were then compared to
data from the BNC1994 (Burnard 2007).

There are several issues with the presentation and interpretation of the results. First,
the quantitative results should be viewed with caution because the textbook corpus
explored was relatively small and no statistical testing was carried out so that is it
unclear whether many of the observed differences between the textbook and reference
corpora may simply be due to random variation. Second, the interpretation of the
results seems somewhat removed from the original pedagogically-orientated aim of
the study. For instance, Zarifi & Mukundan (2012: 13) report that 67% of all phrasal
verb occurrences in their textbook corpus involve the particles *up, down* and *out*. The
authors go on to suggest that these results "can be viewed as a deviation of the
textbooks from natural use of the language since combination [sic] of 8 particles with
20 lexical verbs has been reported to account for about half of all the combinations
in natural language" (Zarifi & Mukundan 2012: 13). However, the study they refer
to, Gardner & Davies (2007), reports that the most productive verb particles in
British English are, indeed, in the following order: *out, up, back* and *down*. Adding
the relevant frequencies presented in Gardner & Davis (2007: 346) reveals that *up,
down* and *out* account for 58% of all phrasal verb occurrences in the BNC1994, which
is not far off the 67% figure observed in the textbook corpus.

It is also worth bearing in mind that both the token frequencies of phrasal verbs and the number of different types of phrasal verbs varies greatly across different text registers (see, e.g., Liu 2011). It is striking that Zarifi & Mukundan's (2012) textbook corpus only includes textbooks' representations of spoken English, whereas the BNC1994 consists of 90% written registers. Thus, a more meaningful comparison benchmark for this particular Textbook English study may have involved Liu's (2011) study, which reports on the frequency counts of the 150 most frequent phrasal verbs across different registers of the BNC1994 and the Corpus of Contemporary American English (hereafter COCA; Davies 2009; 2010). In fact, on the basis of the detailed results provided in Liu's (2011) appendix, it is possible to calculate that about two-thirds of the most frequently occurring phrasal verbs in spoken registers feature the particles *up, down* and *out*.

Other studies comparing frequency lists across a textbook corpus and a reference
corpus have sometimes relied on differences in frequency ranks to evaluate the
linguistic content of EFL textbooks. Mukundan & Roslim (2009), for instance, discuss
supposed differences in the representations of prepositions between Textbook English
and naturally occurring English by comparing the frequency ranks of a corpus of ESL
textbooks and frequency rank data from the BNC1994. As illustrated in Table 2, the
reported rank comparisons do not include the actual frequencies; hence, it is
impossible to grasp how large any observed difference in rank actually is. In addition,
it is quite reasonable to assume that register differences between the textbooks and
the BNC1994 data alone could account for such discrepancies in frequency order. For
instance, the high percentage of complex, professionally written texts in the BNC is
likely to contribute to a higher frequency of noun phrases and consequently to a more
frequent occurrence of the preposition *of* as reported in Table 2.
<table><caption>Table 2: Comparison of the order of the most frequent prepositions in the BNC1994 and three Malaysian ESL textbooks (reproduced from Mukundan & Roslim 2009: 24)</caption><thead><tr><th>Rank</th><th>BNC</th><th>Textbooks</th></tr></thead><tbody><tr><td>1</td><td>of</td><td>to</td></tr><tr><td>2</td><td>in</td><td>of</td></tr><tr><td>3</td><td>to</td><td>in</td></tr><tr><td>4</td><td>on</td><td>on</td></tr><tr><td>5</td><td>by</td><td>from</td></tr><tr><td>6</td><td>at</td><td>at</td></tr><tr><td>7</td><td>from</td><td>by</td></tr><tr><td>8</td><td>after</td><td>after</td></tr><tr><td>9</td><td>between</td><td>before</td></tr><tr><td>10</td><td>under</td><td>between</td></tr><tr><td>11</td><td>before</td><td>near</td></tr><tr><td>12</td><td>behind</td><td>under</td></tr><tr><td>13</td><td>near</td><td>behind</td></tr><tr><td>14</td><td>in front of</td><td>in front</td></tr></tbody></table>

In sum, whilst such corpus-based frequency list comparisons between textbook and reference corpora can produce interesting and pedagogically valuable results, great care must be taken to choose a suitable baseline unit and the appropriate reference corpus, featuring comparable registers – lest the comparison resemble that of apples and pears. Furthermore, providing full quantitative results and/or applying robust statistical testing is essential to the generation of authoritative results.

### 2.1.2.2 NLP methods

This section attempts to shed light on how corpus-derived word frequency lists may also be used in combination with more complex statistical and natural language processing (NLP) methods to investigate the language of English textbooks. This is illustrated with a method designed to evaluate the development of linguistic complexity across three series of high school Taiwanese ESL textbook series (Chen 2016; 2017).

The method first involves calculating several well-established readability measures for each of the main reading texts of the textbooks. Some of these measures involve phonological analyses of the texts (i.e., they require a tool to identify syllable boundaries) whilst others attempt to account for the complexity of the grammatical
structures (which usually requires part-of-speech tagging or dependency parsing). These measures are combined with an analysis of the vocabulary coverage of the textbook texts. This is computed by extracting the content words from each text and comparing them to a list of the most frequent content words in the BNC1994. Counted from the top of this corpus-based frequency list, the coverage rates of each 1,000-word band is calculated as a percentage. This calculation is repeated for the top thirteen 1,000-word frequency bands, with each percentage representing the proportion of the words in each text that is found in these 1,000-word bands from the BNC1994 list. A variability neighbour-based clustering algorithm is then applied to evaluate the text's complexity on the basis of all of these different measures calculated for each text.

The aim of the method is to tease out relative differences in text difficulty between the textbook texts across the various textbook volumes within each textbook series. Contrary to Chen's (2016) hypothesis that the progression of lexical difficulty ought to be unidirectional – in other words, that both the range of vocabulary and textual structure complexity of the reading texts should increase volume by volume – the results point to some striking non-linear developmental stages of text difficulty across the volumes of the three textbook series.

An advantage of such a method is that it combines a large number of linguistic complexity metrics into one measure that can be used to easily compare the linguistic complexity of texts across different textbooks and textbook series. However, like all of the frequency-list approaches discussed so far, the method requires a suitable reference corpus to produce meaningful results. Furthermore, such methods always involve some arbitrary assumptions as to the appropriate size of the frequency bands employed (i.e., should the analysis focus on the 100, 500, 1,000 or 5,000 most frequent words in any one category?). Hence, no matter how complex, the validity and reliability of such methods remain difficult to ascertain.

Chen (2017) developed an alternative metric, which instead of relying on readability measures, attempts to model the lexical sophistication of textbook texts by examining trigrams, i.e., strings of three consecutive word forms, e.g., a lot of. In accordance with his previous research, Chen (2017) concludes that the textbook volumes for advanced learners do not necessarily feature higher degrees of lexical sophistication than previous textbooks in the same series. An advantage of using trigrams to model linguistic complexity is that they also capture valuable information on probabilistic estimates for multiword expressions, thus potentially also revealing relevant developmental trends in the representations of collocation and colligation patterns across textbook texts, volumes, and series.
One methodological issue that remains, however, is that the results of such models are dependent on the number of texts per textbook volume, as well as text length and sentence length. Whilst it may be countered that the latter two are, in fact, desirable features since text length and sentence length may be considered valid factors of lexical and grammatical complexity in their own right, the models nevertheless conflate several variables, thus severely complicating the interpretation of the results that emerge from them. More generally, a major disadvantage of basing Textbook English descriptions and/or evaluation on such complex statistical methods is that the results are highly opaque. If a break in the progression of linguistic complexity across a textbook series is observed, as Chen (2016; 2017) does, it is very difficult to determine which of the many variables entered in the model made consequential contributions to this break in order to understand how improvements could potentially be made. Thus, the pedagogical value of such methods appears relatively limited. Access to such methods is furthermore complicated by the slow uptake of Open Science practices in computational linguistics (see, e.g., Belz et al. 2021; Wieling, Rawee & van Noord 2018). Indeed, it remains relatively common to present new innovative NLP-based methods at conferences and in publications, without ever publishing the corresponding code that would enable (corpus) linguists to apply and assess the methods on new data and research questions.

### 2.1.2.3 Corpus-based comparisons of ‘real-life’ language to textbook language

The corpus-based methodologies outlined thus far have relied on corpus-based frequency lists and have thus tended to revolve around the word level. By contrast, the following sections outline comparative corpus-based methodologies applied to the study of Textbook English with the aim of arriving at quantitative and qualitative descriptions of more complex lexico-grammatical features, their functions and pragmatic uses. We begin with Dieter Mindt’s pioneering corpus-driven method for the analysis of Textbook English, first described in a monograph on the usage and teaching of future constructions in English (Mindt 1987).

Mindt’s interest in textbook language stems from his belief that foreign language textbooks are traditionally based on a pre-conceived grammatical syllabus, rather than on an empirical grammar of actual usage by native speakers (Mindt 1987: 11). He claims that both the grammar syllabus and its content – i.e., the functions of the different grammatical structures – are constructed from two non-empirical, indeed almost anecdotal, sources. He identifies the first as “a longstanding tradition of English language teaching” and the second as “the accepted grammatical knowledge as we find it in current handbooks of English grammar” (Mindt 1997: 40), thus pointing to the cyclical nature of traditional pedagogical grammars. Although his textbook corpus analyses focus on German EFL textbooks, he believes this notion of
a grammatical syllabus to also be true of EFL textbooks published in other countries
(Mindt 1997: 40-41).

At the most basic level, the idea behind Mindt's (1987: 9) approach to the analysis
of Textbook English is:

> Ein aus Analysen von Sprachkorpora gewonnenes Bild der sprachlichen Realität des heutigen
> Englisch wird verglichen mit dem Abbild der englischen Sprache, wie es in zwei verbreiteten
> Lehrwerken dargeboten wird [to compare the results of analyses of authentic English usage
> that provide a picture of the linguistic reality of present-day English with that of the English
> language as it is presented in two series of popular [German EFL] textbooks].

As described in 2.1.1.2, page-by-page analysis of textbook language is a difficult, error-
prone and time-consuming process. The development of digital data storage and
retrieval enabled Mindt to pioneer a new approach to language textbook analysis
work using computer-readable textbook corpora. The first step consists in compiling
a corpus of naturally occurring, and in Mindt's case, native speaker English. From
this data, Mindt extrapolates an empirical grammar of future time expressions that
is exclusively based on the observed phenomena, thus breaking with the tradition of
introspection-based, deductive grammars. In a third phase, he proceeds with a
comparison of the frequencies, functions and co-occurrences of future expressions
found in a corpus of two series of popular German EFL textbooks with those from
his authentic corpus, the latter thus representing target learner language. Mindt's
study of future time expressions in English exemplifies this methodology (1987, 1992).

In this first corpus-driven Textbook English study, Mindt explores the future
constructions featured in textbooks designed for lower secondary school
(*Sekundarstufe 1, Hauptschule, Klassen 5 - 10*). His reference corpus combines a
corpus of English conversation (34 spontaneous recordings of conversations of native
British English speaking adults, ca. 170,000 words) and a corpus of contemporary
British plays (all published between 1963 and 1980), which he considered to be written
representations of natural, spoken language (totalling ca. 184,000 words). Mindt
(1987: 50) justifies his choice of a spoken English reference corpus by arguing that
the German education authorities stipulate that foreign language teaching at this
level should aim to enable students to be able to communicate in everyday situations.
His textbook corpus consists of two series of five textbooks each from the two largest
publishers of school material in Germany. His analysis focuses exclusively on the
language presented in the coursebooks and thus excludes all accompanying material
such as workbooks, test material, vocabulary books, and, crucially, the transcripts of
the listening exercises (Mindt 1987: 53).

Mindt's approach begins with a comparison of the two reference sub-corpora before
comparing these results with those from the analysis of the textbook corpus.
Hierarchical and centroid-based cluster analyses are applied to group both reference
sub-corpora. To test the homogeneity of the clusters, i.e., whether differences between
the various independent groups are significant, a chi-square test is then applied.
Mindt (1987: 62–73) argues that the combination of these two procedures produces a
“core description” of the frequencies and co-occurrences of future expressions in
spoken British English, which he then goes on to compare to the claims made in
major English grammar works and, finally, to the language presented in the two
German EFL textbook series. Thus, Mindt’s approach involves inferring an empirical
grammar inductively, moving from language data to grammatical generalisation, as
opposed to the more traditional, deductive approaches that rely on previously
ascertained prescriptive rules. Empirical grammars may then be drawn upon to
generate pedagogical grammars.<fnref n="11" />

Since Mindt (1987) first exemplified the method by investigating the representations
of the future in German EFL textbooks, numerous Textbook English studies have
emerged which have, at least partially, been inspired by the Mindtian approach:
comparing computer-readable real-life L1 corpora with textbook corpora. So far, these
have also focused on specific, individual lexico-grammatical features, such as support
verb constructions (Sinclair & Renouf 1988), the indefinite pronouns *any* and *some*
(Tesch 1990), modal auxiliaries (Römer 2004b), the progressive aspect (Römer 2005)
and *if*-conditionals (Gabrielatos 2013; 2019; Römer 2004a; 2007). Key insights from
these studies will be presented in part two (Section 2.2).

2.1.2.4 Comparing textbook language to ‘real-life’ language

Another approach to exploring the lexico-grammatical content of language textbooks
is to manually extract groups of lexico-grammatical features from EFL textbooks and
compare these and their frequencies to a reference corpus. This methodology may be
perceived as a reversal of Mindt’s methodology described in 2.1.2.3. Instead of
deriving an empirical grammar of specific features of English from an English L1
corpus to then compare it to the way these features are presented in EFL textbooks,
this approach begins with the textbook grammar and attempts to apply it to data
extracted from a corpus of naturally occurring English. As this approach, and
variations on it, have been applied in many a textbook study, in the following,
Koprowski’s (2005) analysis of lexical phrases featured in EFL textbooks and
Gabrielatos’ (2003; 2006; 2013) explorations of textbooks’ typologies of conditionals
will serve to exemplify the approach.

In an investigation on the usefulness of the lexical phrases presented in contemporary
textbooks, Koprowski (2005) manually extracted all the lexical phrases explicitly
presented in three intermediate EGP coursebooks. He then compared these 822 lexical

<footnote n="11">¹¹ In the following, the term ‘pedagogical grammar’ will be used according to Dirven (1990: 1) for whom the term ‘pedagogical grammar’ covers both learning and teaching grammars.</footnote>
items to data retrieved from five subcorpora of the COBUILD corpus. To this end, a
"usefulness score" was calculated for each lexical item extracted from the textbooks.
This score relies on two criteria: frequency, arguing that "the commonest units in the
language are the ones most likely to be met by learners outside the classroom and
should therefore be at the centre of the learning program" (Koprowski 2005: 324) and
range, which refers to the number of text types in which a phrase is commonly found,
on the grounds that "a unit which exists in a wide variety of registers is generally
considered much more useful than an item found in just one, even if that item is
highly frequent" (Koprowski 2005: 324). Koprowski's (2005) results are rather
disconcerting: 14% of the lexical phrases explicitly featured in the coursebooks were
found to be entirely absent from the COBUILD corpus (Sinclair et al. 1990) (see
2.2.1.2 for more details of the results).

‘Reversed Mindtian’ approaches have also been applied to analyses of Textbook
English focusing on grammar and here, too, have pointed to the inadequacy of
pedagogical grammars in EFL textbooks. For instance, Gabrielatos (2003; 2006; 2013)
examined the typologies of conditional sentences presented in a range of intermediate
to advanced EFL textbooks. He identified five types of ELT typologies and concludes
that the majority of the coursebooks examined largely follow a simple conditional
typology consisting of three types: first conditional with *will*, second and third
conditionals with *would*. The most elaborate ELT typologies also include the so-called
*zero* conditional, the use of epistemic modals, imperatives, and a range of tenses in
all the conditional types. Next, Gabrielatos extracted a random sample of *if*-sentences
from the written sections of the BNC1994 and annotated them according to their
conditionality, tense and aspect marking, time reference, modality, etc. Using these
annotations, he calculated how many of these naturally occurring *if*-sentences can
accurately be described according to the ELT conditional typologies presented in EFL
textbooks. Using the most basic typology, only 15% of the *if*-sentences from the BNC
could be successfully classified. Most strikingly, even with the most complex and
inclusive of the ELT typologies identified in the textbooks, 22% of all sentences are
still unaccounted for. These results lead Gabrielatos (2006: 2) to conclude that the
typology explicitly taught in textbooks “provides learners with an incomplete, and in
some cases distorted, picture of *if*-conditionals”.

Contrary to Mindt’s studies, Gabrielatos’ method only explores ELT grammar as
presented in the textbooks’ grammar sections, rather than, more holistically, to the
totality of the language to which learners are exposed via their textbooks.
Methodologically, such ‘reversed Mindtian’ approaches have the disadvantage of only
pointing to the inadequacy of Textbook English without providing textbook authors
and EFL teachers with those “useful” (to keep with Koprowski’s terminology)
linguistic features that are missing from or grossly underrepresented in textbooks but
which corpus-based studies have demonstrated to be highly frequent and salient.
Though a much more time-consuming undertaking, the compilation of a textbook corpus, in addition to the qualitative analysis of their grammar sections, allows for the analysis of how specific linguistic features are represented in the textbooks' reading passages, exercises, instructions and listening transcripts. Following such an approach, Winter & Le Foll (forthcoming) revealed that a remarkably large proportion (between 43% and 53% depending on the typology applied) of if- conditionals featured in 42 secondary school EFL textbooks did not fit the conditional typologies presented in these same textbooks; thus highlighting a significant gap between what is taught in textbooks and what is practiced by textbook authors within these same textbooks (on conditionals in EFL/ESL textbooks, see also Gabrielatos 2006; 2013; Römer 2004a; 2007; Tesch 1990).

### 2.1.2.5 Elicitation approaches

The previous section explained how lexical units or grammar rules extracted from EFL textbooks can be compared to reference corpus data to form judgements as to how “useful” (e.g., Koprowski 2005) or “accurate” (e.g., Gabrielatos 2003; 2006; 2019) textbook input is likely to be for foreign language learners. In the following, a different approach to evaluating the authenticity of textbook language will be described. It relies on the re-creation of communicative situations simulated in the textbooks. In this respect, it can be said to share some characteristics with the ‘reversed Mindtian’ approach described in the previous section.

In a study of spoken discourse features in Textbook English, Gilmore (2004) investigates the authenticity of the language presented in service encounter dialogues (e.g. hiring a car from a rental shop, or asking for directions in the street) in ten EFL textbooks published between 1981 and 2001. To this end, he selected one such dialogue from each textbook and extracted, in note form, all the questions asked by the information receiver in each dialogue. The questions were then reformulated and used as a basis for real conversations in the genuine settings imagined by the textbook authors. The real dialogues were recorded and transcribed and subsequently used to compare the use of discourse features in the textbook dialogues and their ‘authentic’ re-creations.

Gilmore’s (2004) method is highly original, yet it appears difficult to draw conclusions on results based on just seven textbook dialogues and seven enactments. Critically, the authentic nature of semi-staged service encounter dialogues (and, though this is not specified in the publication, perhaps even with the researcher acting as the information receiver in each of the re-created dialogues) may be questioned. Furthermore, it would be interesting to investigate to what extent discourse features of the conversations would differ if the information receiver were a non-English native speaker, since the majority of these service encounter dialogues are intended to
present typical communicative situations that tourists may face in an English-
speaking country.

In a similar vein, Schauer & Adolphs (2006) explore the possibility of using native speakers' responses to discourse completion tasks, rather than large-scale native speaker corpora to inform the teaching of formulaic sequences in the EFL classroom. Expressions of gratitude featured in four EFL textbooks were compared to those elicited in discourse completion tasks, as well as to thanking formulae retrieved from the spoken CANCODE corpus. Unsurprisingly, the researchers observe notable differences between the controlled, elicited responses and the natural conversations found in the corpus. They argue that the first type of data can facilitate the acquisition of more recent language pattern changes, whilst the latter can generally provide “[a] much broader picture” such as “insights into the procedural aspects of expressing gratitude”, which may materialise in the form of collaborative negotiation or re-lexicalisation of another speaker’s utterance (Schauer & Adolphs 2006: 130).

In sum, it is tempting to conclude that constructed dialogues, whether in the form of semi-staged re-enactments of textbook dialogues or discourse completion tasks, are unlikely to yield sufficiently robust data to reliably evaluate the authenticity of textbook language. Nonetheless, such methodological approaches can point towards aspects of textbooks that may need to be updated or re-organised. They can thus provide valuable starting points for further investigations.

### 2.1.2.6 Adding learner corpora to the equation

A number of studies explore Textbook English with a view of better understanding learners' interlanguage. Since textbooks constitute a major source of secondary school learners' L2 input (see 1.6), it may be speculated that learners' over-, underuse or misuse<fnref n="12" /> of particular lexico-grammatical features may be (at least partly) attributed to their textbooks' treatment of these features. In order to investigate such potentially causal relationships, some studies have attempted to triangulate results derived from textbook vs. reference corpora comparisons with insights from learner corpora (e.g., Fujimoto 2017; Gabrielatos 2013; Möller 2020; Rankin 2010; Vine 2013; Winter & Le Foll forthcoming). The potential and limitations of such methodologies are exemplified in the following.

An example of a study drawing on textbook data to glean insights into English learners' difficulties is Rankin's (2010) study of adverb placement in L2 essay writing. In this study, 37 English essays written by Austrian university students were surveyed

<footnote n="12">¹² Note that, unlike ‘misuse’, the terms ‘overuse’ and ‘underuse’ are descriptive, not prescriptive, terms; they merely refer to the fact that a linguistic form is found significantly more or less in the learner corpus than in the reference corpus.</footnote>
for adverb placement errors. The errors were checked against the Louvain Corpus of Native English Essays (LOCNESS; Granger 1998) and tagged. In parallel, all the pedagogic material used during the students' English language course (the duration of which is not mentioned) was gathered; materials and exercises specifically dedicated to adverbs were tallied. In other words, Rankin's study exclusively looks at explicit practice of adverbial usage, rather than at all the lexico-grammatical constructions involving adverbs to which learners were exposed in class. In the qualitative part of the analysis, Rankin (2010) compares the students' adverb placement errors with the classroom input material. He concludes that whilst the adverb grammar exercises provided often require learners to choose appropriate adverbs for particular gaps in gap-filling exercises, they do little to address the issue of adverb placement within sentences. He stresses that "residual problems with adverb placement are not due to any major deficiencies in basic grammar but rather to the fact that appropriate variation in adverb placement for special discourse and pragmatic contexts has not been mastered" (Rankin 2010: 214).

In another example of an English Textbook study involving learner corpus data, Fujimoto (2017) examines the use of the present perfect simple with and without temporal adverbials across three corpora: a longitudinal learner corpus of Japanese university students' academic writing assignments, a textbook corpus consisting of "reading passages" drawn from six high school English textbooks and a reference corpus consisting of the fiction and general prose subcorpora of the FLOB (representing British English of the early 1990s; Hundt, Sand & Siemund 1998) and Frown (representing American English of the early 1990s; Hundt, Sand & Skandera 1999) corpora. The frequencies of the co-occurrences of the present perfect simple with temporal adverbials in the reference corpora are compared to the corresponding frequencies extracted from both the learner corpus and the textbook corpus. As Fujimoto demonstrates, such L1 vs. textbook vs. learner corpora comparisons can provide relevant insights into the source of learners' difficulties with regards to specific lexico-grammatical features. However, in this case, it may be argued that the FLOB and Frown fiction and general prose subcorpora are questionable baselines for comparisons of reading texts from secondary school textbooks and student academic writing. Academic writing is known to follow quite typical register-specific lexico-grammatical patterns and the study fails to account for such register discrepancies.

Following a similar procedure, Vine (2013) computed the frequency of four high-frequency category ambiguous words (*down*, *like*, *round* and *up*) across English native language (hereafter ENL) corpora (spoken and written British English and New Zealand English), learner English corpora (spoken and written) and an EFL textbook corpus. Comparisons of the frequencies of occurrences of each of these four words sorted in terms of the grammatical category of each use revealed considerable variations across all the corpora. It is interesting to note that whilst Vine subdivides