Filling the ___-s in F innish MWE lexicons (2020)

Abstract: This paper describes the automatic construction of FinnMWE: a lexicon of Finnish Multi-Word Expressions (MWEs). In focus here are syntactic frames: verbal constructions with arguments in a particular morphological form. The verbal frames are automatically extracted from FinnWordNet and English Wiktionary. The resulting lexicon interoperates with dependency tree searching software so that instances can be quickly found within dependency treebanks. The extraction and enrichment process is explained in detail. The resulting resource is evaluated in terms of its coverage of different types of MWEs. It is also compared with and evaluated against Finnish PropBank.

## introduction this paper describes the automatic construction of a lexicon of finnish multi-word expressions (mwes) derived from data in english wiktionary and finnwordnet @xcite . a specific issue which is pronounced in -but by no means unique to -finnish is is that of government. consider the following examples: the perspective taken here is that such governance restrictions can be treated as simply another type of multiword. one justification for this approach is to consider an english transliteration of 1a where the elative case ending is translated using the preposition "from", i.e. the literal "i hold from cake". if we consider a hypothetical dialect of english where this was synonymous with "i like cake", then we could conceive of "hold from" as a prepositional verbal multiword. these types of multiwords can be presented to humans in multiple ways, for example "pitää ___-sta" (to like), given just there in the author's preferred form of a gapped multiword, would commonly be presented in one of two other forms in a typical dictionary of finnish. the first is as part of a headwords, where gaps would instead be rendered with an inflected pronoun e.g. "pitää jostakin", (@xmath0. alternatively, the gap might be specified in a grammar notes next to a particular word sense, in which case the entry under the headword pitää corresponding to "to like" would have a note "~+ elative" where ĩndicates the headword. given this information is already specified in dictionaries, the focus of this paper is upon extracting it, alongside other types of finnish multiwords, and making them machine readable so as to interoperate with other resources and systems. the type of specifications given alongside individual definitions on wiktionary go beyond simply verbpredicate argument-case associations, and include other types of morphological valency information, as well as constituent words, syntactic valency information (e.g. transitive/intransitive), fine-grained pos information (e.g. auxiliary), and occasionally semantic valency information. a complimentary view on these these lexical items is that they are dependency tree templates, since, excepting semantic valency information, all this information is available within a universal dependencies (de @xcite parse tree. this perspective makes the simplifying assumption that a verb's arguments are its descendants within a dependency tree, which is not always the case. beside these syntactic frames, and more straightforward multiwords, the resource also includes inflections as another form of non-lemma idiomatic construction. of interest is whether an inflected form is given a definition. if it is, this is a reasonable indication of idiomatic usage. ## related work related to this work are verb oriented semantic valency, or predicate-argument structured, lexical knowledge bases (lkbs) such as propbank @xcite and framenet @xcite . for finnish, in this category there are finnish propbank @xcite , finnframenet @xcite and finntransframenet @xcite . the verbal frames within these resources do not concern themselves with syntax or morphology and can to some extent be preserved across languages, and so information about language specific issues such as the case in which a nominal argument appears are only visible through corpora annotated with these schemes. in contrast, verbnet is a fairly language specific formalism. its frames give a great deal of specific semantic information about verbs, and also include syntactic restrictions on the parts of speech of arguments. in the case of the basque verb index @xcite , which was inspired by the verbnet formalism, this includes case information on arguments. outside of verbnet inspired formalisms, but within the uralic languages, @xcite created a resource for northern saami, with both morphological and semantic category restrictions upon arguments, allowing identification of situations when the incorrect case had been used within a grammar checking application. the approach in this paper is novel in its selection of initial data and the extent to which it is exploited. english wiktionary gives definitions for words from many languages in english. focussing in on the definitions of finnish words on english wiktionary, it can be seen as a unidirectional finnish-english bilingual dictionary. as such, while it is written for everyday usage by a general audience, it is directed somewhat towards second language learners. the level of grammatical detail is thus driven by this intended audience, rather than by a specific linguistic formalism. while previous work in automatic creation of lkbs from existing resources such as dbnary @xcite , conceptnet @xcite , and babelnet @xcite have made heavy use of wiktionary, for the most part, detailed information about grammatical constructions has been neglected. ## method the overall pipeline of linguistic data resulting in the finnmwe resource is shown in figure 1 . the processing is performed with python. for accessing finnwordnet, nltk @xcite is used, while wiktionary data is processed from the raw mediawiki xml dumps using mwparserfromhell . identispan tokenise lex parse interpret figure 2: pipeline to parse grammatical usage notes within wiktionary definitions. ## evaluation for headwords with high normalised mutual information, the syntactic frame information from wiktionary and the semantic frames of finnish propbank co-alternate. this means that the syntactic frames under this headword correspond to different senses according to the held-out lkb of propbank. currently, the most fragile part of the processing pipeline is the extraction of information given within the body of wiktionary pages, in particular the syntactic frame data. the reason is that this information is given as free text, and is only as consistent as it is by-convention, and so a wiktionary editor could decide to introduce new conventions at any time. therefore, one reasonable direction is to introduce more structure upstream. on more the conservative side, the current conventions on wiktionary could be encoded into official template tags. a longer term solution would be to make sure this type of data can be encoded within the lexicographical data section of wikidata.