DUDU : A Treebank for O ttoman T urkish in UD Style (2025)

Abstract: This paper introduces a recently released Ottoman Turkish (ota) treebank in Universal Dependencies (UD) style, DUDU. The DUDU Treebank consists of 1,064 automatically annotated and manually corrected sentences. The texts were manually collected from various academic or literary sources available on the Internet. Following preprocessing, the sentences were annotated using a MaCHAMP-based neural network model utilizing the large language model (LLM) architecture and manually corrected. The treebank became publicly available with the 2.14 release, and future steps involve expanding the treebank with more data and refining the annotation scheme. The treebank is the first and only treebank that utilizes the IJMES transliteration alphabet. The treebank not only gives insight on Ottoman Turkish lexically, morphologically, and syntactically, but also provides a small but robust test set for future computational models for Ottoman Turkish.

## introduction among several treebank projects, the universal dependencies treebank project establishing a cross-linguistically consistent treebank annotation scheme for many languages @xcite , stands out as the largest collection of treebanks sharing the same annotation scheme @xcite . although ud has numerous treebanks for modern languages, historical languages such as ottoman turkish remain significantly underrepresented. this paper introduces the dudu treebank, one of the first ottoman turkish treebanks annotated in the universal dependencies (ud) style. the dudu treebank consists of 1,064 latin-transliterated automatically annotated and manually corrected sentences from various genres. the treebank employs the standard ottoman turkish transliteration alphabet to handle the alphabet change. ## background languages from historical periods have always been an engrossing research topic for scholars. the proliferation of computational linguistics methods has accelerated such research in the recent years (e.g., @xcite ), and ud treebanks project is the manifestation of this process. the ud treebanks aim to provide the sentence's lemma, universal part-of-speech tag (upos), xpos, and mapping for the relationship between arguments (dependency) (see @xcite for further explanation). the language analyzed in this paper is ottoman turkish, the official and literary language of the ottoman empire @xcite and "a variant of the perso-arabic script" consisting of 31 letters @xcite . it was used from the 14th century until the 20th century, up until the decision taken by the republic of turkey in 1928 to replace with latin script @xcite . unlike the boun treebank ( özates ¸et al., 2024), another treebank for ottoman turkish in ud, the dudu treebank utilizes ijmes transliteration system to prevent information loss caused by alphabet changes and includes the gender feature, which is absent in modern turkish but crucial in ottoman turkish grammar. ## data a total of 1,064 automatically annotated and manually corrected sentences consisting of 10,012 tokens and 10,287 syntactic words which indicates that 273 tokens are fused forms that are split into multiple syntactic words. the longest sentence has 91 words while the shortest has two words. the treebank includes 3,133 lemmas and 15 universal pos tags. the morphological annotation covers 67 unique features, including number distinctions (singular: 5,816 instances; plural: 1,001 instances; dual: 3 instances), gender (female: 644 instance; mascular: 110 instances), proper name type (e.g., geography: 173; person: 334), and tense/aspect marking (e.g., past: 1,067 instances; present: 489 instances). among 38 unique dependency relations, the most common dependency relations are obliques @xcite , noun modifiers (1,291 instances), and objects (657 instances). various written works from 14th to 20th century were collected as data. sentences were from various topics including biographical texts, national newspapers, religious texts, fictional works such as stories, instructional texts, popular culture articles, and essays. the main purpose of including data from various registers was to initiate a creation of a representative treebank for the language. the texts were collected from various academic journals, dissertations, and literary sources on the internet. the texts were transcribed from perso-arabic letters to latin by domain experts; however, with some mistakes. in this research, the latin transcribed versions were utilized. this initial work focuses on laying the foundation for future research on ottoman turkish by leveraging existing modern turkish treebanks and llm models instead of focusing on establishing a large treebank. ## methodology in the annotation process, both automatic and manual annotation were leveraged. initially, we created a seed dataset with only 85 sentences by correcting and manually transforming ottoman turkish sentences into their modern equivalents. these sentences were later used to train the annotation model with existing modern turkish treebanks, as detailed in the following three subsections. once the initial treebank was created, a model trained on the ottoman turkish data was used to annotate unseen sentences without manually transforming phase, which were manually corrected. following the manual correction phase, these sentences were added into the training dataset and the model retrained. this iterative process significantly improved annotation efficiency. ## challenges the main challenge was due to the fact that the ottoman turkish language was affected by arabic and persian not only lexically, but also grammatically @xcite . this meant a comprehensive knowledge of turkish, as well as arabic and persian, was required to address these challenges. the main two challenges related to arabic elements in ottoman turkish were noun phrase structure in arabic and gender feature. firstly, dataset contains several arabic phrases as fixed expressions. since they function as single units and were mostly idiomatized in ottoman turkish, they were treated as single units. a good example of this is fi'l-vâk . i'. the phrase, formed with the preposition fi' (meaning "in") and the noun vâk . i' (meaning "fact"), is in a noun phrase structure and translates to "in fact" or "indeed". such fixed expressions were shown as single units rather than as separate ones, as shown below: on the other hand, we chose to split non-fixed arabic noun phrases, since each lexical component contributes to the sentence with its morphological and syntactic features, as seen in the s ¸eyhü'l-beled ("the religious leader of the town") example, below: another challenge emerged from the gender feature in arabic and persian words. although the gender of words in noun phrases is irrelevant in turkish, because there is no gender agreement, in arabic, the words involved in the noun phrase must have the same gender @xcite . gender plays a significant role in ottoman turkish noun phrases and the automatic annotation model did not assign the gender feature due to the absence of gender information in the training data. thus, the gender feature was manually added during the post-processing when necessary. this enrichment aimed to better reflect the linguistic characteristics of ottoman turkish in the treebank. furthermore, ottoman turkish, particularly in religious texts, often contains entire sentences in arabic. to reduce the complexity of the work, such sentences from the treebank were excluded. the challenge related to persian features in ottoman turkish was mainly aroused by izafet, "by which the head of a noun phrase was linked to the modifying noun or adjective that followed it" @xcite . in persian noun phrases, the suffix attaches to the modifier rather than the head noun. if the phrase includes a head noun and an adjective, the suffix applies to the adjective, marking the entire phrase. although not grammatical in modern turkish, this structure is common in ottoman turkish. an example of izafet from the dataset can be h . uk . ûk . -u mes ¸rû' (meaning "legitimite rights"). in such cases, during the post-processing phase, the morphological analysis of the adjective, which functions as the modifier, was manually corrected as shown below. in ## conclusion and future work to conclude, the dudu treebank, as the first ottoman turkish treebank using the ijmes transliteration alphabet, provides a foundation for further research on different aspects of the ottoman turkish language, particularly in lexical, morphological, and syntactic analysis, but also beyond these areas. furthermore, it also demonstrates that a model trained in the treebanks of a language's present-day form can be utilized for the analysis of its low-resourced historical form, in this case, ottoman turkish leveraging llm. future work will focus on expanding the treebank with more data to serve a wide spectrum of language use in ottoman turkish and adding new features which modern turkish lacks; however, ottoman turkish has. unfortunately, for this version, the genres cannot be separated by sentence ids. the order of the sentences is chronology-based rather than genre-based, and the earliest written sentence is at the top. in addition, it is planned to add the original form of the sentence in perso-arabic letters to the treebank. lastly, we plan to publicly release the trained model, which is trained on the final dataset, on the internet to make it available accessible for further research. in the end, the treebank was created by the first author of this paper with the name dudu and was published in the ud v2.14 release 1 . the work is currently in progress to expand the treebank to at least 20,000 words for the next release.