Function Multiword Expressions Annotated with Discourse Relations in the R omanian Reference Treebank (2024)

Abstract: For the Romanian Reference Treebank, a general language corpus, covering several genres and annotated according to the principles of Universal Dependencies, we present here the annotation of some function words, namely multiword conjunctions, with discourse relations from the Penn Discourse Treebank version 3.0 inventory of such relations. The annotation process was manual, with two annotators for each occurrence of the conjunctions. Lexical-semantic relations of the types synonymy, polysemy can be established between the senses of such conjunctions. The discourse relations are added to the CoNLL-U file in which the treebank is represented.

## introduction one important characteristic of a text is its cohesion, i.e., the presence of linguistic cues to guide the reader into making connections between the ideas expressed therein @xcite . one such linguistic cue are the connectives, with conjunctions being one subtype thereof and the focus of this paper. we identify the occurrences of conjunctions in a corpus that is already morpho-syntactically annotated, the romanian reference treebank @xcite , and annotate them with discourse relations from an inventory already applied at a larger scale @xcite , namely that from penn discourse treebank (pdtb) version 3.0 annotation manual @xcite . the aim of our endeavour is to identify the possible senses romanian conjunctions have, as well as to find the possible lexical devices to express these discourse relations in romanian, particularly in this corpus. as a further step, we aim to use these annotated occurrences of conjunctions as training material for understanding the structure of a text. we start by presenting similar initiatives of annotating connectives with pdtb inventory of discourse relations (section 2) and then outline the system of romanian conjunctions (section 3). the annotation method we adopted is described in section 4 and the obtained results are presented in section 5 and are then discussed in section 6, before concluding the paper and envisaging further steps (section 7). ## romanian inventory of conjunctions romanian conjunctions are devices for expressing either coordination or subordination. the former function both at the clause level and at the sentence level, connecting words and, respectively, clauses entering the same syntactic relation with their head: in ex. (1) the conjunction and connects two direct objects, and in ex. (2) it connects two clauses functioning as direct objects. subordinating conjunctions, however, are only clause linking devices (complementizers), linking a subordinate clause to the clause containing its syntactic head (ex. (3)). one conjunction is either subordinating or coordinating, never both. in romanian linguistics, the class of conjunctions is made up of conjunctions and conjunctive locutions. as far as their structure is concerned, conjunctions are simple (e.g., cȃ "that") or compound (e.g., ca sȃ "so that", fiindcȃ (lit. 'being that') "because"). as one can notice, the latter can be written either as distinct words (e.g., ca sȃ) or as a single word (e.g., fiindcȃ). conjunctive locutions are always made up of at least two (separate) words (e.g., pentru cȃ 'for that' "because"). under focus in this paper are only the conjunctive locutions, though further annotation will extend to simple and compound conjunctions as well (see section 7). a remark is necessary here with respect to the romanian conjunction sȃ. this is a complementizer that specialized as the subjunctive mood marker @xcite . it can occur in main clauses, where it is only a subjunctive marker (ex. (4)), but it can also occur in subordinate clauses, where its status varies, depending on the presence of absence of another subordinating device (be it another conjunction or a relative pronoun or adverb): it is either (a) both a subjunctive marker and a complementizer when (i) no other subordinating device is present (ex. (5)), or (b) only a subjunctive marker when the clause is introduced by a relative pronoun or a relative adverb (ex. ( 6 )). there are also cases when sȃ is a component (the last one in linear order) of a conjunctive locution: e.g., fȃrȃ sȃ "without s ȃ", pentru ca sȃ "so as to". for the analysis of sȃ in rrt, the relation mark foot_0 is always used to attach it to the verb in the subjunctive mood, irrespective of whether it is also a complementizer or only a subjunctive marker. consequently, the relation fixed, used for fixed expressions that are function words, cannot be used for attaching sȃ as the last component in a conjunctive locution, thus resulting into an inconsistent treatment of conjunctive locutions in romanian ud treebanks: in those that do not contain sȃ the components are linked the relation fixed to the first component in linear order (figure 1 for example (7)), while in those containing sȃ this component is not attached to the rest of the expression, but is treated like a separate word (figure 2 for example (8)). ## work methodology the corpus. we chose to annotate the conjunctions in the romanian reference treebank (rrt) @xcite . the corpus contains 9,523 sentences and 218,511 tokens, distributed in several genres. it is released and distributed within universal dependencies foot_1 (de marneffe et al., 2021), thus being tokenized, lemmatized and morphosyntactically annotated according to the principles thereof. the inventory of discourse relations. for annotation we used the discourse relations defined in the pdtb 3.0 manual. there are three levels on which relations are defined here, from more general too more specific (see figure 3 ). the most refined level was always used in the annotation process. the inventory of conjunctions. the aim of this work presented here is to specify the discourse relation expressed by each occurrence of conjunctive locutions in rrt. we started from a list of such conjunctions extracted from the morphological, orthographic and orthoepic romanian dictionary (doom, 3rd edition) 3 , 71 of which were found in rrt with a total number of 479 occurrences. annotators. the data underwent double annotation, with a linguist and a student contributing to this task. the former was already familiar with the pdtb 3.0 manual, while for the latter this was the first experience of the kind. the degree of agreement between them is presented in the methodology. each occurrence of the conjunction was annotated independently by each annotator. only one relation was assigned, always at the lowest level possible in the pdtb hierarchy 3 https://doom.lingv.ro/ (figure 3 ). only in a couple of cases, when the context was not considered enough to identify the sense or to distinguish between two senses, no annotation was assigned or, respectively, two senses were assigned. ## results all occurrences of conjunctive locutions in rrt were annotated. in the annotation is added to the conll-u format foot_2 of rrt. in figure 4 we present the current annotation of the sentence in example (9). the information about the discourse relation is added on the last column of the file: the same number is used in this last column to identify the components of the conjunctive locution, while the label of the discourse relation appears only with the first component foot_3 : see the highlighted lines in figure 4 , where number 1 is added in the last column of the first occurrence of components of the conjunction pentru cȃ, number 2 is used for the second occurrence of the same conjunction, while the discourse relation expressed by each appears only for the first component, in each occurrence. conjunction dupȃ ce pentru cȃ în timp ce înainte de pentru ca sȃ astfel încât "after" "because" "while" "before" "in order to" "so that" no. 87 54 51 35 33 27 accuracy 89 70.4 86.3 100.0 93.9 88.9 conjunction pe mȃsurȃ ce chiar dacȃ as , a încât as , a cȃ fȃrȃ sȃ înainte ca "as" "even if" "so that" "so that" "without" "before" no. 16 13 10 9 9 9 accuracy 75.0 100.0 100.0 100.0 77.8 100.0 conjunction astfel cȃ cu toate cȃ de îndatȃ ce pânȃ când "so that" "although" "as soon as" "until" no. 8 8 7 5 accuracy 87.5 25.0 28.6 100.0 ## discussion of results we notice in one of the relatively frequent (35 occurrences) conjunctions which is specialized for a relation is înainte de "before", which expresses tempo-ral.asynchronous. precedence. the fact that not all pdtb relations occur in these tables does not mean they are not lexicalized in romanian or by these conjunctions; it simply means that the analysed conjunctions in this corpus do not express them. there are cases when one conjunction expresses two senses for the same occurrence: see the case of dupȃ ce which is assigned two senses for 38 occurrences: temporal.asynchronous.succession and contingency.cause.reason. this is expected not to be a singular case, as this is also reported for pdbt @xcite . for the moment, we were not able to find any correlations between the text genre and the relation expressed by a conjunction, nor between the order of arguments and such relation. ## conclusions and further work our work so far ensured the familiarity of annotators with the pdtb annotation manual and the inventory of discourse relations thereof. this is this annotation can help drawing comparisons between cross-lingually equivalent conjunctive locutions, which is of paramount importance in translation (be it manual or automatic). corpora anno-tated with discourse relations are used in training, tuning and testing of systems for discourse parsing, which romanian lacks at the moment. understanding such relations between parts of a text is vital in many nlp applications (from question-answering and summarization to automatic reasoning). as conjunctions are not the only means of expressing discourse relations, we also envisage extending our work to the annotation of adverbs and other textual connectors and, eventually, to identify-proceedings of clib 2024