Dialectal treebanks and their relation with the standard variety: The case of East Cretan and Standard Modern Greek (2025)

Abstract: We report on the development of the first treebank and parser for Eastern Cretan in the framework of Universal Dependencies (UD). Eastern Cretan is a living but under-resourced dialect of Modern Greek. We have worked on the transcription of oral material and relied on active annotation and knowledge transfer from GUD, a treebank of Standard Modern Greek. Along with its other phonological and morphosyntactic differences from Standard Modern Greek, Eastern Cretan (and other varieties of Modern Greek) makes heavy use of euphonics and voicing that have not been included in the UD annotation guidelines so far. We have provided annotation guidelines for East Cretan euphonics and voicing and included them in the models. Knowledge transfer from the treebank of Standard Modern Greek to the dialectal models helped to initiate annotation via an active annotation procedure

## introduction the leaps in nlp in recent years have brought considerable efficiency to language analysis tools. this rapid progress has reduced the cost of the oral material-to-linguistically annotated text pipeline and facilitated knowledge transfer from well resourced languages to less resourced ones. at the same time it is challenging because the resulting representation of the less resourced languages may be biased by the massive evidence collected for the richly resourced ones @xcite . in the face of the increasingly rapid digitization characterising our era, it is a matter of survival for underresourced languages to gain an independent digital presence that respects their individual nature so that they can be integrated into modern technologies and methods of study. considering dialects, the available linguistic data are not only scarce but are also often characterized by a significant lack of consistency in their orthographic representation. this is due to the primarily oral nature of these language varieties. since our goal was to create language models capable of understanding the current linguistic reality, it was essential to rely on contemporary speech data. the eastern cretan treebank foot_0 is the first morphosyntactically annotated treebank of a living modern greek dialect. annotation complies to the universal dependencies -version 2 (ud.v2) guidelines @xcite . for standard modern greek (smg) there are two ud.v2 treebanks, gdt and gud, with gud being the most recent one foot_1 . gud contains 1,807 sentences (25,493 tokens) randomly selected from fiction texts. we trained models on the eastern cretan treebank only, and on the eastern cretan treebank plus the gud (henceforth eastern cretan+gud), to see whether and to what extent smg can contribute to the development of eastern cretan language models. in section 2, the basic linguistic differences of the eastern cretan dialect from smg are briefly presented. in section 3, we present the linguistic resources we used and in section 4, we provide details about the compilation of the treebank and the handling of specific morphological and syntactic phenomena. in section 5, we discuss the annotation method, and in section 6 and 7, we present and comment on the models we developed. in the last three sections we present the limitations of our approach and the conclusions we reached. cretan is a language variety of modern greek (mg) primarily spoken on the island of crete and by the cretan diaspora. this includes communities of cretan descent who relocated to hamidieh in syria and western asia minor after the 1923 population exchange between greece and turkey. the preservation and development of the dialect have been influenced by crete's long-term isolation from the mainland and the island's domination by non-greek-speaking powers such as the arabs, venetians, and turks for more than nine centuries. cretan is divided into two main dialect groups -western and eastern-based on phonological, morphological and lexical characteristics. the two groups share a lot of features that characterise the cretan dialects. the division aligns with the island's administrative boundaries between the prefectures of rethymno and heraklion. the phenomenon of the gradual decline of mg dialects in the face of smg is observed. beyond the social and economic reasons for the depopulation of rural areas, which are the natural speaking environments for these language varieties, efforts to preserve and reproduce them have not yet taken on a systematic character. specifically, the dialects have not been systematized regarding their orthographic representation and are not taught. unlike most other mg dialects, cretan is not endangered and remains widely used as the primary mode of communication in many parts of the island. however, as all mg dialects, it is underresourced, in particular with regard to resources that would support its presence in the contemporary technological landscape. below we will mention some of the distinctive features that the cretan dialect retains, according to the studies by @xcite . phonological level 1. palatalization and affrication of /k/, /g/, /x/, /g/ before the phonemes /e/, /i/. the corresponding cretan allophones in the aforementioned phonetic environment are respectively: [ù], [dý], [c], [ý] 2. fricativation of /t/ to /t/ and /d/ to /d/ before semivocalic phonemes: • [ta 'ma. tça] → [ta 'ma. tça] • [ku.ve.'dja.zo] → [ku.ve.'ðja.zo] 3. realization of the @xmath0, <ντ>, <@xmath1, [d], [g] without the nasal element in any position. 4. development of the euphonic sounds [e], [n], and [j] to avoid hiatus in cases of word coarticulation (see also section 4.3): • <τον bάνř>, [ton 'va. no] → <τονe bάνř>, [tone 'va. no], 'ι put him' • <ούτe όμπìασe>, ['u.te 'o.bja.se] → <ούτe νόμπìασe>, ['u.te 'no.bja.se], 'nor did it swell' • <η αfορμή>, [i a.for.'mi] → <η @xmath2.for.'mi], 'the occasion' 5. elision of the final /n/ in the genitive plural: • [ton spit.'çon] → [to spit.'ço] 6. stress on the fourth syllable from the end as opposed to smg where the so-called 'law of three syllables' demands that no word carries a stress beyond the third syllable from the end. • [ef. 'ta.ksa.me.ne] • [e.'fi.ga.me.ne] 7. development of prothetic /a/ or /o/. • [a.mo.na.'xos] • [og.'ńi.go.ra] morphological level 1. use of different article forms than smg. • <τση>, the.gen.fem.sg, [tsi] instead of @xmath3, [tis] • <τσì>, the.acc.f.pl, [tsi] instead of @xmath4,[tis] • <τσοì>, the.acc.masc.pl, [tsi] instead of @xmath5, [tus] 2. inflection @xmath6: • <έxομe>, ['e.xo.me], instead of @xmath7, ['e.xu.me], 'we have' • <κάνομe>, ['ka.no.me], instead of @xmath8, ['ka.nu.me], 'we do' 3. several masculine nouns @xmath9: • <το ńαός>, [to la.'os].neuter, instead of @xmath10, [o la.'os].masc, 'the people' • <το πńούτος>, [to 'plu.tos].neuter, instead of @xmath11, [o 'plu.tos].masc, 'the wealth' 4. extension of forms of demonstrative pronouns: • <τοuτοσές>, [tu.to.'ses], instead of @xmath12, ['tu.tos], 'this.nom.masc.sing' • <eκeìοσές>, [e.cio.'ses], instead of @xmath13, [e.'ci.nos], 'that.nom.masc.sing' 5. verbs ending @xmath14: • <xορeύgř>, [xo.'re.vgο] instead of @xmath15, [xo.'re.vο], 'i dance' 6. in both smg and cretan, the future tense is expressed periphrastically. in contrast to smg, which employs one auxiliary element, cretan uses two: the subordinating @xmath16. the @xmath17: either in its indeclinable form, which is considered the infinitive form @xmath18, or in finite form, but only for the singular (chairetakis, 2020), e.g., • infinitive form: <να πας tέńeì>, [na 'pas 'te.li], 'you will go' • finite form: <να πας @xmath19, 'you will go' • instead of @xmath20, [ta 'pas], 'you will go' 7. the use @xmath21, [ks] as a perfective aspect marker: • <τραgούδηξα>, [tra.'gu.di.ksa] instead of @xmath22, [tra.'gu.di.sa], 'i sang' lexicological level in the cretan dialect, a wealth of words is attested that are not found in smg. most of these words are loanwords from turkish and venetian. the influence of each of these languages on the cretan dialect spans four centuries, with turkish linguistic influences being comparatively stronger due to the fact that the turkish conquest was more recent. these loanwords are frequently used to name objects and processes related to the material culture of the people. finally, the cretan dialect also attests to stereotypical expressions not found in smg. for the transcription of the recorded speech to text, the whisper large-v2 model was utilized. at the time this process was carried out (april 2023), whisper large-v2 returned the best results to small trials with the cretan data. the transcriptions were edited by a linguist who is native speaker of the eastern cretan dialect. given that the cretan dialect is primarily an oral language variety, there is no standardized orthography. the general trend in the orthographic representation of cretan is conformity with that of standard modern greek. we followed that trend, in an effort to strike a balance among facilitating knowledge transfer from gud, representing the linguistic characteristics of the dialect in the orthography and aligning with the dominant orthographic trends adopted by the dialect's native speakers. the handling of the distinctive phonological phenomena of the cretan language variety, such as the frequent insertion of euphonic sounds and the occurrences of voicing, will be discussed below. ## the treebank the annotation of east cretan has relied on the ud annotation guidelines for gud. 3 only deviations and new constructs and forms have been documented in the guidelines for the east cretan treebank that are listed as comments of the gud guidelines. ## active annotation to annotate the cretan treebank we used active annotation @xcite implemented in 6 iterative cycles. the first set of 40 unlabelled cretan samples was annotated with a model trained on gud, which represents smg. in each cycle, the annotator edited 40 samples from the output, split in 30 for the training set and 10 for the development set, added them to the existing training and development sets and the model was retrained on the revised data. for the test set, 30 manually annotated samples were used. all samples were randomly selected, with the only criterion being that each sample contained more than five tokens to avoid sentences with minimal linguistic information. during this first attempt to develop a ud treebank of cretan, the annotation guidelines were developed as research progressed. any revisions to the annotation guidelines were implemented across the entire training, development and test sets. ## including euphonics and voicing in the models to introduce euphonics in the model, we process the input connlu representations of sentences by transferring information from the mseg annotation (column 10 of the connlu format) on the lemma, upos and xpos columns and training the model on the modified treebank 4 . the original word's upos and deprel tags are inherited by the piece of the token that remains after the euphonic is removed (the 'original word') and the euphonic is represented as a separate token with the new xpos/upos tag euph that depends on the original word with the new dependency relation 'euph'. the xpos tag euph and the dependency 'euph' have been defined for the purposes of the eastern cretan treebank and are used in ongoing work on other varieties of modern greek, including smg. the tag euph was introduced to the upos column to satisfy a requirement of the processing tool. we did not use the upos x because euphonics can hardly be called words, at least in the sense of self-standing linguistic entities that combine a form with some type of semantic contribution. but even if euphonics were considered a type of word, again the x upos would not be a choice because euphonics are clearly parts of the language varieties we study and play a well defined role. these two facts contrast with the ud annotation guidelines about upos x: "(upos) x is discouraged for words that clearly belong to the language, even if they are idiosyncratic in form or distribution and thus do not neatly fit into other syntactic categories." neither did we use the upos part(icle). ud define particles as "function words that must be associated with another word or phrase to impart meaning and that do not satisfy definitions of other universal parts of speech". euphonics do not impart any meaning at all. finally, we did not consider them clitics as suggested by one of our reviewers, because clitics do not define a pos of their own and we have argued that euphonics cannot be assigned any of the pos available in ud. the output of the model that knows about euphonics cannot be used in the active annotation cycle because its form differs from the form of the ud treebank. this output contains a modified xpos column (which may not be a problem), no information on the misc column about voicing and euphonics while the upos column is modified with an extra tag. we have not applied active annotation on voicing and euphonics but for future needs, since the phenomena occur in many mg dialects, we will have to post-edit the model's output and make it comply with the form of the annotation of the input. α complete example is included below featuring the @xmath23, singular, accusative form of the personal @xmath24. similarly, the feature-value pair "@xmath25. ## discussion the results are depicted in in a 7th training round, we applied on the eastern cretan treebank the transformation that introduces euphonics and voicing in the models (see section 4.3). the results are shown on ## conclusion we have developed the first ud treebank of eastern cretan, which is a living, non standardised variety of modern greek. we have attempted to model phenomena new to ud guidelines such as voicing and euphonics; these phenomena abide in the dialects of modern greek. the successful active annotation procedure and the knowledge transfer from the gud treebank of smg to the models of eastern cretan suggests that a similar pipeline can facilitate the modelling of other varieties of mg, starting from western cretan. we hope that this treebank will support future efforts to provide additional digital material from more native speakers, the textual legacy of east cretan as well as other, linguistically challenging, dialects of modern greek.