PARSEME-IT Issues in verbal Multiword Expressions identification and classification
Authors: Johanna Monti, Valeria Caruso, Maria Pia di Buono (Università di Napoli L'Orientale, University of Zagreb, 2018)
Topic: Lexical and Semantic Resources and Analysis

Abstract
The second edition of the PARSEME shared task was based on new guidelines and methodologies that particularly concerned the Italian language with the introduction of new categories of verbs not considered in the previous edition. This contribution presents the novelties introduced, the results obtained and the problems that emerged during the annotation process and concerning some categories of verbs.

Introduction
The paper reports on some ﬁnal results of the second edition of an annotation trial for verbal Multiword Expressions (VMWEs) carried out on the Italian language by the PARSEME-IT research group 1, which started within the broader European PARSEME project, the IC1207 COST action ended in April 20172. The initial project is expanding in this second stage of its development, thanks to a wider network of research groups, working together as one 1https://sites.google.com/view/ parseme-it/home 2https://typo.uni-konstanz.de/parseme/ of the ACL Special Interest Group on the Lexicon, called SIGLEX-MWE. In its ﬁrst edition, the PARSEME shared task released a corpus of 5.5 million tokens and 60,000 VMWE annotations in 18 different languages which is distributed under different versions of the Creative Commons license. To increase the computational efﬁciency of Natural Language Processing (NLP) applications, PARSEME focuses on a special class of Multiword Expressions which have been seldom modelled for their challenging nature, such as verbal MWEs (Savary et al., 2017). Many of the features of this particular type of MWE are considered to be difﬁcult to cope with, such as the discontinuity they present (turn it off) the syntactic variations they license (the decision was hard to take), the semantic variability resulting both in literal and idiomatic readings (to take the cake), or the syntactic ambiguity of many forms (on is a preposition in to trust on somebody, but a particle in to take on the task). Moreover, these units have language-speciﬁc features, and are generally modelled according to descriptive categories developed by different traditions of linguistic studies. The PARSEME research group thus addresses also the creation of a multilingual common platform for VMVEs using universal terminology, guidelines and methodologies for the identiﬁcation of these units cross-linguistically. Moreover, at the end of the ﬁrst annotation trial a shared task on automatic identiﬁcation of VMWEs was also carried out and has proved the reliability and usefulness of the data collected so far, which have been already presented and discussed (Savary et al., 2017; Monti et al., 2017). The paper illustrates the types of VMWEs used by the second PARSEME annotation trial more thoroughly. In Section 2 we provide a brief description of the second annotation trial of the PARSEME shared task together with the statistics. Then we present a new category of verbal MWEs, namely Inherently Clitic Verbs (Section 3) and in Section 4 two very productive categories in Italian (IRV and IDV). In Section 5, we discuss some borderline cases which posed some classiﬁcation issues. Finally, we conclude and discuss future work.

Conclusion
In this paper we described the novelties concerning the PARSEME shared task on automatic identiﬁcation of verbal MWEs - edition 1.1 (2018), in which new verb categories have been included in comparison with the 2017 edition. Some of them are language-speciﬁc, such as ICV for some Romance languages, others are not, like IAV. The increased number of categories enables to annotate corpus data more thoroughly, and discover a broad range of combinatorial phenomena that present different degrees of opacity. We also discussed two productive categories in Italian, namely IRV and VID, and analyzed LVC and IAV borderline cases together with observations on combinatorial phenomena that can be applied in order to annotate VMWE more effectively. Future work includes a further linguistic analysis of borderline cases in order to contribute to the description of these phenomena.