First Insights into the Syntax of S lovene Student Writing: A Statistical Analysis of Šolar 3.0 vs. Učbeniki 1.0 (2025)

Abstract: This study investigates the syntactic features of Slovene student writing by comparing essays from the Šolar 3.0 corpus (ages 13–19; primary and secondary school levels) with textbook texts from the Učbeniki 1.0 corpus aligned to the same educational stages. We apply quantitative syntactic analysis at two complementary levels: clause-type frequency (coordination, parataxis, and four types of subordination) and tree-based syntactic complexity measures (number of clauses, clauses per T-unit, and maximum parse-tree depth). Results show that students heavily rely on coordination and specific subordinate clauses (especially object and adverbial), producing more clauses per sentence and per T-unit than textbooks. However, their sentences tend to exhibit flatter syntactic structures, with shallower embedding in primary school and only modest increases in tree depth by secondary school. These findings reveal a divergence between surface-level complexity and hierarchical depth, highlighting developmental trends and instructional targets in written syntactic maturity. We conclude by discussing implications for syntactic development and directions for future research.

## introduction in recent years, the availability of large scale corpora annotated with syntactic relations, improved accuracy of automatic parsing tools, and userfriendly software for corpus-data extraction have opened new opportunities for syntactic research based on automatically processed linguistic data. this paper investigates the use of syntactic structures in the writing of slovene primary (age 13-15) and secondary (age 15-19) school students, using the developmental šolar 3.0 corpus (arhar holdt and @xcite , and compares it to the syntactic patterns found in the corpus of slovene textbooks-učbeniki 1.0 @xcite . the šolar 3.0 corpus comprises 5,485 slovene texts (1,635,407 words) produced by pupils in grades 6-9 of slovene primary school (ages 13-15) and by students in slovene secondary school @xcite . its composition reflects the variety of classroom genres: essays (58.7%), classroom exercises (15.0%), practical texts (12.6%), and tests (13.7%). just under one fifth of the texts (19.7%) come from primary students, with the remainder (80.3%) authored by secondary-school students. most texts (85.4%) were written in slovene language classes. although teacher corrections are available for 38.18% of the corpus, our analysis uses the original student productions to capture authentic student syntax. to ensure better comparability in genre and communicative purpose, we restrict our analysis to texts labeled as esej ali spis (essay), which constitute the majority text type in šolar. the učbeniki 1.0 corpus consists of 127 slovenelanguage textbooks (4,302,857 words) covering grades 1-9 of primary school and all years of secondary school, across 16 subjects. primary school textbooks make up 71.6% of the corpus, with secondary school titles accounting for 28.4%. for direct comparability with šolar 3.0, we restrict our analysis to grades 6-9 of primary school and all secondary school textbooks, excluding readers and early grade textbooks. this alignment ensures that both corpora reflect the pedagogical materials and student texts relevant to the same educational stages. although the two corpora differ in genre, comparing them is sensible: textbooks-written for these age and comprehension levels-represent the intended or desired level of language competence, while students' texts reveal their actual writing skills. we cannot, however, be sure that textbook authors intentionally or successfully tailored their language to the target age group. situated within the domain of literacy develop-ment, this study aims to provide a clearer picture of how syntactic competence manifests in student writing compared to the standard slovene patterns promoted through pedagogical materials. the analysis relies on corpus data @xcite obtained via the universal dependencies foot_0 (ud) framework and represents the first computational syntactic study of student writing in the slovene context. as a starting point, we ask: to what extent do student texts differ syntactically from textbook texts, and how can these differences be meaningfully interpreted? can such insights yield pedagogically useful guidance for developing writing competence? to answer these questions, our quantitative analysis proceeds on two complementary levels: together, these approaches yield a richer account of student syntactic development. the findings offer practical implications for language instruction, highlighting which clause types and complexity dimensions merit explicit teaching, and to what extent students' real world usage aligns with textbook models. this work was conducted within the framework of the empirical foundations for digitally-supported development of writing skill foot_1 project, which supports applied linguistic research for educational development. the remainder of this paper is organized as follows. section 2 provides related work. section 3 describes data-preparation procedures and the methodology for the quantitative syntactic analyses, including clause-type frequency counts and tree-based syntactic complexity measures. section 4 reports the results of these analyses for primary and secondary school subsets. section 5 offers a discussion of our findings. finally, section 6 provides our conclusion and outlines avenues for future work. ## related work computational syntactic analysis of slovene corpora has only recently gained significant momentum, primarily due to advancements in syntactic parsing following the universal dependencies (ud) framework. this cross-linguistically consistent annotation scheme, having been developing for over the past decade, has enabled more sophisticated analyses of slovene syntactic structures. the current version of the classla-stanza parser @xcite has achieved remarkably high accuracy rates of 95.54% for ud-relations in slovene texts, making large-scale automated syntactic analysis increasingly reliable. recent studies have begun to leverage udannotated corpora for slovene linguistic research. @xcite explored the potential and limitations of ud-relations for analyzing spoken slovene, highlighting the adaptability of the framework to various contexts. @xcite demonstrated the value of ud annotations for comparative syntactic analysis by automatically measuring syntactic complexity differences between written and spoken slovene corpora. research on the šolar developmental corpus has thus far focused primarily on lexical aspects of student writing. @xcite analyzed collocations occurring within the corpus, while gantar and bon (forthcoming) investigated multi-word lexical challenges faced by students in slovene primary and secondary schools. arhar holdt and @xcite examined the most frequently corrected verbal and pronominal lemmas in the corpus, aiming to develop data-driven instructional materials responsive to actual student needs. by contrast, syntactic dimensions of student writing remain largely unexplored. this is a notable gap given the importance of syntactic development in educational contexts and the potential for corpusbased findings to inform pedagogical practice. the present study addresses this gap by providing the first quantitative analysis of slovene student syntax compared to textbook models, leveraging the analytical power of ud annotations to reveal developmental patterns in syntactic complexity and clause usage across educational levels. although slovene-based studies are scarce, re-search on as a first language (l1) writing provides valuable developmental benchmarks and comparative context for assessing syntactic growth across educational levels. in their studies of adolescent writing in english l1 in the united states, beers and nagy ( 2009); (2011 ) examined clause density-measured as clauses per t-unit-among other syntactic complexity measures, across various essay types. for grades 7 and 8 students (ages 12-14), beers and nagy (2009) reported a mean of 1.5 clauses per tunit in narrative essays and 2.0 in persuasive essays. in a broader study of types of school writing, beers and nagy (2011) analyzed texts from grades 3, 5, and 7, finding that grade 7 (ages 12-13) clause density ranged from 1.21 in descriptive texts to 2.08 in persuasive essays. since the šolar corpus essays are not subdivided by types, the average of the four essay types reported by beers and nagy (2011)-1.46 clauses per t-unit-offers a useful reference point for interpreting clause density at the primary-school level in the present study. a foundational study by @xcite further supports these benchmarks. his analysis of 8th-grade (ages 13-14) student writing revealed an average of 1.42 clauses per t-unit, indicating slightly lower syntactic complexity in u.s. school settings compared to the average across essay types reported by beers and nagy. as for the secondary level, hunt (1970) reported a mean of 1.68 clauses per t-unit for 12th-grade students (ages 17-18), suggesting moderate syntactic growth in late adolescence. this figure provides a relevant benchmark for evaluating clause density in the secondary-school subset of the present study. these studies also emphasize two important caveats: first, that increased syntactic complexity does not always correlate with higher writing quality; and second, that genre exerts a significant influence on syntactic structures. different genres give rise to distinct syntactic realizations, depending on their communicative goals. therefore, syntactic complexity should be interpreted in light of genre conventions rather than as a standalone indicator of writing development. ## results in this section, we present the results of the quantitative analyses, organized by educational level. we first report findings for the primary-school texts, followed by those from the secondary-school level. at each level, we examine both clause-type frequencies and tree-based syntactic complexity measures. ## discussion this study provides novel insights into syntactic patterns characterizing slovene students' written language in comparison to pedagogical patterns represented in textbooks. by employing a dualmethodological framework-quantitative analyses of clause-type frequencies and tree-based syntactic complexity measures-we uncover distinct patterns in how students utilize syntactic structures at both primary and secondary school levels. before interpreting these findings, it is impor-tant to consider the genre makeup of each corpus. the šolar 3.0 corpus used in this study includes only student essays, while the textbook corpus encompasses a broader mix of descriptive, expository, and narrative texts. this genre imbalance partially explains clause chaining in student writing, which may amplify the frequency of coordination and subordination in comparison to textbooks.