I ’ve got a construction looks funny – representing and recovering non-standard constructions in UD (2020)

Abstract: The UD framework defines guidelines for a crosslingual syntactic analysis in the framework of dependency grammar, with the aim of providing a consistent treatment across languages that not only supports multilingual NLP applications but also facilitates typological studies. Until now, the UD framework has mostly focussed on bilexical grammatical relations. In the paper, we propose to add a constructional perspective and discuss several examples of spoken-language constructions that occur in multiple languages and challenge the current use of basic and enhanced UD relations. The examples include cases where the surface relations are deceptive, and syntactic amalgams that either involve unconnected subtrees or structures with multiply-headed dependents. We argue that a unified treatment of constructions across languages will increase the consistency of the UD annotations and thus the quality of the treebanks for linguistic analysis.

## introduction the universal dependencies (ud) initiative is a project that aims for crosslinguistically consistent annotation of morphosyntax (de @xcite . the sharing of representations across languages is intended to support multilingual nlp applications on the one hand and to facilitate the linguistic study of similarities and differences from a typological perspective. while the ud framework also covers the annotation of parts of speech and of morphological features, the annotation of syntactic dependencies is at its core. ud currently uses 37 labels for broadly attested grammatical relations. in addition to these basic ud dependencies, ud allows for an enhanced representation that "aims to make implicit relations between content words more explicit by adding relations and augmenting relation names" @xcite . the most prominent examples of added relations in enhanced representations are links that help propagate relations over conjunctions. while the basic dependency structure is assumed to form a (possibly non-projective) tree, enhanced ud representations often no longer are trees. the subtyping of relations serves to capture more fine-grained language-specific constructions @xcite . for instance, in english, subjects of passive clauses bear the relation nsubj:pass. in this paper, we discuss several constructions that are found in spoken language and data from social media, which are not trivial to analyze. the first set of constructions involves cases where a head and dependent are related in a hybrid way, exhibiting for instance properties of both coordination and subordination, or of coordination and predication. the second group of constructions involves syntactic amalgams where arguably the assumption that a basic ud analysis should form a tree is not met. we discuss possible trade-offs with respect to how basic and enhanced ud relations might be used in these cases to give linguistically adequate analyses. note that, our unmarked examples come from twitter. the others come from the ukwac corpus @xcite , ud treebanks, or the linguistic literature. ## constructions with hybrid properties we first discuss constructions that superficially look as if a head and dependent are connected by a certain relation but where the construction also, or even mainly, exhibits properties of another type of relation. ## syntactic amalgams we now turn to two constructions where arguably a basic ud analysis mirroring the analyses proposed in the theoretical literature from the construction grammar tradition would not result in simple trees and which for that reason need some special treatment. ## conclusion we have presented several constructions that are associated with social media or spoken language and that have special properties that do not readily fit the current use of basic and enhanced ud relations. the first set of constructions involved pseudo-coordinations whose surface structure is mismatched with their semantics. the second set of constructions featured cases of syntactic amalgams that either involved unconnected subtrees (double is) or structures with multiply-headed dependents (pac). while one can disagree both with the analyses of these constructions in the theoretical literature and with our ideas for dealing with them in ud, we are confident that as ud treebanks expand to more languages, domains, genres and registers, further constructions with similar challenges will be encountered. to allow for consistent and expressive analyses, we think the ud community would benefit from discussing which mechanisms to use for which kinds of constructions. we have explored the use of enhanced ud annotations, keeping the relation inventory the same, and as an alternative introducing new dependency relations and relation subtypes, which may lead to sparsely attested relation types. one option we have not explored but which the gum corpus uses is a kind of constructional annotation (specifically, of sentence types) in the metadata @xcite . this would, however, not localize which words are part of the construction. other ways to track constructions may be conceivable. whatever the annotation mechanisms used, we think that adding linguistic analyses for such constructions to the ud guidelines might help to improve annotation consistency across languages, and thus the quality of the treebanks. existing ud treebanks already feature some well-represented constructions that are treated inconsistently between treebanks and/or languages along the lines we discussed. for instance, the two clauses of the paratactic correlative construction (the x-er, the y-er) are related by conj in german treebanks (hdt @xcite , tüba @xcite , gsd @xcite ), while english treebanks (ewt, gum @xcite ) mostly use advcl.