Multiword Expressions We Live by: A Validated Usage-based Dataset from Corpora of Written Italian
Authors: Francesca Masini, M. Silvia Micheli, Andrea Zaninello, Sara Castagnoli, Malvina Nissim (Università di Bologna, Università di Milano Bicocca, Zanichelli Editore, Università di Macerata, University of Groningen, 2020)
Topic: Lexical and Semantic Resources and Analysis

Abstract
The paper describes the creation of a manually validated dataset of Italian multiword expressions, building on candidates automatically extracted from corpora of written Italian. The main features of the resource, such as POS-pattern and lemma distribution, are also discussed, together with possible applications.

Introduction
The computational treatment of multiword expressions (henceforth, MWEs) is notoriously a major challenge in NLP AUTHOR. In the last decades, the (computational) linguistics community has dedicated many efforts to the development of techniques for the (semi-)automatic identification and extraction of MWEs from corpora and the consequent creation of resources, such as gold standard lists of MWEs, which are needed for evaluation tasks or machine learning training. This notwithstanding, the availability of such resources is still quite limited compared with “the ubiquitous and pervasive nature of MWEs” AUTHOR, especially for `non-mainstream' languages like Italian. With this work, we contribute to this line of research by providing a dataset of 1,682 validated Italian multiword expressions, obtained through the manual annotation of candidates automatically extracted from corpora of written Italian within the CombiNet project AUTHOR. The dataset is to be intended as a first release that will be enriched in the future. We describe our methodology in Section~sec:method, while in Section~sec:results we report on preliminary analyses carried out with respect to MWE features and distribution.

Conclusion
The sequences contained in this release are obviously quite heterogeneous. Semantically speaking, some are very idiomatic in meaning (e.g. braccio di ferro ‘arm wrestling’, colpo di scena ‘coup de théâtre’, mandare in onda ‘to broadcast’), some other (much) less so (e.g. prendere le distanze ‘to distance (oneself)’, andare in pensione ‘to retire’, di servizio ‘service (adj.)’), their specialty lying more in their familiar, conventional status (e.g. sapere benissimo ‘to know (damn) well’, essere favorevole ‘to be in favour’, nella storia ‘in history’). Still others may have more than one meaning, with different degrees of figurativity (e.g. mettere in scena, which can mean both ‘to stage’ and ‘to enact’). From a formal point of view, some look rather fixed and do not admit lexical insertion (e.g. vero e proprio ‘proper’) or inflection (e.g. tra l’altro ‘by the way’, ordine del giorno ‘agenda’), whereas others seem more flexible (e.g. essere certo ‘to be sure’, andare bene ‘to be OK, to go well’, posto di lavoro ‘workplace’). MWE variability is one aspect that we did not address here but definitely deserves to be investigated more thoroughly (cf. e.g. (Nissim and Zaninello, 2011)). In fact, some MWEs may exhibit different behaviour and even completely different meanings according to their grammatical form, like, for example, a suo tempo ‘in due course’ (lit. in his/her time) vs. ai suoi tempi ‘in his/her time’ (lit. in his/her times). Being based on lemmatized forms, our study does not currently account for such form differences. Moreover, our study is based on contiguous sequences, therefore discontinuous or topicalized occurrences are not accounted for. We also aim at broadening this initial list by exploring more candidates from the CombiNet data, which are obviously still rich of relevant material. This first release, although limited, is meaningful since it is the first list of commonly used MWEs available for the Italian language, except for domain-specific resources such as PANACEA (Frontini et al., 2012). Although lexicographic material is now accessible for Italian lexical combinatorics (see e.g. (Lo Cascio, 2013)), usagebased and freely available lists of MWEs are still missing and much needed, both for computational tasks and for applied (lexicographic and language teaching related) purposes.