S inhala Dependency Treebank ( STB ) (2023)

Abstract: This paper reports the development of the first dependency treebank for the Sinhala language (STB). Sinhala, which is morphologically rich, is a low-resource language with few linguistic and computational resources available publicly. This treebank consists of 100 sentences taken from a large contemporary written text corpus. These sentences were annotated manually according to the Universal Dependencies framework. In this paper, apart from elaborating on the approach that has been followed to create the treebank, we have also discussed some interesting syntactic constructions found in the corpus and how we have handled them using the current Universal Dependencies specification.

## introduction integrating linguistic information, specifically syntactic information, into language processing tools and applications improves accuracy. this has been proven for applications such as machine translators @xcite and natural language understanding @xcite . it is also shown that explicitly integrating syntactic and semantic information for training pre-trained models such as bidirectional encoder representations from transformer (bert) improves the model's performance @xcite , even though some of the linguistic information will automatically be learned during the model training. this constitutes evidence that data annotated with syntactic information are essential for the development of nlp applications. in addition, linguists also use linguistically annotated data and computational tools to do linguistic analysis. therefore, they also require linguistic resources. like other indic languages @xcite , sinhala is also a low-resource language with a few publicly available resources. de @xcite has surveyed available tools and resources in the sinhala language and reported that no parsers or syntactically annotated treebanks are available for sinhala. however, some parts of speech (pos) and name entity recognition (ner) data are available. in addition, other resources like parallel corpora @xcite are also available. this paper reports the development of the firstever treebank with syntactic annotations for the sinhala language. these annotations are added according to the universal dependencies framework. ## the sinhala language the sinhala language is an indo-aryan language spoken by about 20 million people worldwide. it is one of the two official languages in sri lanka, spoken by 75% of its population. tamil, sanskrit and pali have influenced the sinhala language. although tamil is from a different language family called dravidian, sinhala has been in contact with it for a long time. the portuguese, the dutch, and the english colonized and stayed in sri lanka for centuries. therefore, the influence of the languages spoken by them can be seen in sinhala; several daily words have been borrowed from portuguese and dutch. further, sinhala has linguistic similarities with languages like hindi, bengali, panjabi, and marathi etc. spoken in india and divehi, which is primarily spoken in the maldives. sinhala is a diglossic language which appears in two distinct varieties: spoken sinhala and written sinhala, also known as colloquial sinhala and literary sinhala, respectively. significant differences in these two styles are marked in all levels of the language, including lexical and syntactic levels @xcite . sinhala is a relatively free word order language, though its unmarked word order is sov. different word orders are also possible with discourse-pragmatic effects @xcite . as with most indo-aryan languages, sinhala is also an agglutinative language in which a single nominal element can be inflected for several forms to indicate the grammatical features of the case, number, gender, definiteness and animacy, and a verbal element can be conjugated for that of @xcite . although no work is reportedly done on developing a treebank for sinhala, @xcite have discussed a dependency-based annotation schema for the sinhala language, which has not proceeded to develop a treebank. further, prasanna (2021) has also analyzed the dependency relations of the sinhala language from a theoretical perspective. ## treebank development in this section, we have outlined the steps we followed to create the sinhala treebank. ## discussions this section outlines some of the interesting syntactic constructions found in the treebank. some of these may not be common in other languages. ## issues and challenges this section outlines some of the challenges we encountered during the linguistic analysis and annotation. ## conclusion we have reported the development of the first treebank for the sinhala language, which is annotated using the universal dependencies framework. as a first attempt, we have annotated 100 sentences taken from a contemporary sinhala text corpus. apart from the data selection and the annotation process, we have also given analyses for the interesting constructions found in the data and explained how we had captured them using the current universal dependencies specification.