Developing U niversal D ependencies Treebanks for M agahi and B raj (2021)

Abstract: In this paper, we discuss the development of treebanks for two low-resourced Indian languages - Magahi and Braj - based on the Universal Dependencies framework. The Magahi treebank contains 945 sentences and Braj treebank around 500 sentences marked with their lemmas, part-of-speech, morphological features and universal dependencies. This paper gives a description of the different dependency relationship found in the two languages and give some statistics of the two treebanks. The dataset will be made publicly available on Universal Dependency (UD) repository in the next (v2.10) release.

## introduction magahi is an eastern indo-aryan language, spoken mainly in eastern indian states including bihar and jharkhand, along with some parts of west bengal and odisha. magahi is classified under the eastern group of the outer sub-branch of indo-aryan language @xcite . scholars like turner have clubbed the 'bihari' languages with eastern and western hindi @xcite . there is another kind of classfication of indian language in which western hindi is almost an isolated group while eastern hindi, bihari and other languages of eastern group are clubbed together @xcite . but the classification in which magahi comes under the eastern group of the outer sub-branch of indo-aryan language is the most widely accepted classification. brajbhasha is classified in two ways. according to first classification, brajbhasha is a western indo-aryan language that is spoken in the states of western uttar pradesh and parts of rajasthan @xcite . the other classification puts brajbhasha in the group of western hindi of central group of indo-aryan sub-family of indo european language family along with hindustani, bangaru, brajbhaka, kanauji, bundeli @xcite . the difficulty of tracing the exact historical path of a large number of these indo-aryan languages is discussed in detail by masica @xcite and is evident by somewhat incompatible classification given by chatterji, turner, katre, cardona and mitra and several other scholar @xcite ; @xcite ; @xcite ; @xcite ; @xcite ; @xcite . as such the exact status of magahi and braj vis-a-vis other indo-aryan languages (especially the major ones like hindi, bangla and odia) remains hazy and controversial. this, coupled with the imposition of modern standard hindi (msh) over what is now popularly known as 'hindi belt' and what has historically been established as a rather complex dialect continuum, with several languages and varieties being spoken in different domains of usage @xcite , has resulted in these languages mistakenly classified as varieties of hindi. this, in turn, has resulted in not only minimal support from the government for development of different kinds of resources for the language but also a negative attitude of the speakers towards the language @xcite . however, despite this disadvantageous situation of the language, there has been some efforts at developing language technologies and resources for these languages, especially for magahi viz. monolingual written and speech corpora @xcite , magahi part-ofspeech tagger @xcite and magahi language identification system @xcite . this paper describes another such effort towards developing a universal dependency (ud) based treebank for the language which may prove to be useful in processing and analysing the language for different applications. ## universal dependencies and low-resource languages universal dependencies framework provides some unique advantages for low-resource languages both in terms of making the language for cross-lingual comparison and studies as well as making transfer learning and multilingual techniques for technology development possible. as a result in recent times we have seen the development of ud treebanks for quite a few low-resource languages viz. yorùbá @xcite , latin treebank for ud @xcite , hittite (andersen and rozonoyer, 2020), manx gaelic @xcite , laz @xcite , albanian @xcite and others. the ud treebanks have also been built for indian languages such as bhojpuri, hindi, marathi, sanskrit, tamil,telugu and urdu @xcite . except hindi, all of the (indian) languages mentioned above are low-resourced languages. recently, dash et al. (2021) reported the development of a treebank in santhali, another low-resourced language spoken in india. however, one of the biggest challenges in building treebanks for a large number of lowresource languages is the absence of grammatical descriptions and hence a reference point for deciding on the analysis needed to give the dependency relationships. there are many treebanks that could be roughly classified in two groups. treebanks of well-known and well-described languages like hindi, english, french etc and treebanks of lesser known and sparsely described languages. magahi and braj come in the second group which are sparsely described languages. there have been very few linguistic studies on these lan-guages with both of these languages lacking an exhaustive grammatical description or even a dictionary. these are some linguistics studies towards the description of magahi: a basic (although not completely accurate) description of magahi is given by shila verma @xcite , a description of magahi case system @xcite @xcite , discussion on magahi honorific system within the minimalist framework @xcite , morphosyntactic properties of nominal particle -wa @xcite , and study on the magahi spatial postpositions @xcite . for braj, to the best of our knowledge, the only modern linguistic studies are on its ergativity under the minimalist framework @xcite . . this lack of an exhaustive description of different aspects of magahi and braj morphosyntax made the task of developing the treebank quite challenging and required establishing multiple grammatical analyses of the languages while working on the treebank. the aim of this paper is to give a broad description of magahi and braj morphosyntax within the universal dependencies framework with respect to different syntactic dependency relationships in the languages, along with a discussion on the process of the development of this treebank. ## treebank creation in magahi and braj we annotate the magahi and braj treebank with lemma, universal parts-of-speech (pos) tags, a subset of morphological features and the universal dependency relation. the dependency relation for magahi and braj are annotated using a subset of the 37 dependency relations included in the universal dependency tagset foot_0 . in the following sections, we describe each of the features marked for building magahi and braj dependency treebank. most of these relationships follow the canonical patterns as discussed in the ud guidelines (and as witnessed in common indo-european languages). ## magahi and braj treebank we have used magahi and braj plain text to prepare a treebank. magahi plain text is part of a large monolingual written and speech corpora @xcite , which is prepared from the magahi literature. braj plain text is also prepared from the literary domain @xcite . we have used conllueditor @xcite tool to build a treebank. the tool facilitate us to attach several kinds of information with words like upos, lemma, morph feature and dependency relation among different word of sentence etc. currently, braj treebank has a total of around 5.8k tokens (excluding punctuations) in a total of 500 sentences. magahi, on the other hand, has a total of over 12k tokens ## conclusion in this paper, we have discussed the development of treebanks for braj and magahi -two extremely low-resource eastern indo-aryan languages spoken in india. the treebank is annotated with lemma, upos, morphological features and ud relations. as of now the braj treebank has 500 sentences (with around 5.8k tokens) while the magahi treebank has 945 sentences (with over 12k tokens). a comparative analysis of dependency relation of magahi and braj treebank reveal that, as expected, most of the syntactic relations are shared across the two languages except the two dependency relation in our available dataset. the first one is copula (cop) relation -magahi has a simple syntactic structure of cop while in braj it could have a complex structure and it may vary between two types of lexical structure. the second dependency relation is that of classifier (clf) -magahi has numeral classifier while this is not present in braj.