Dealing with Italian Adjectives in Noun Phrase: a study oriented to Natural Language Generation
Authors: Giorgia Conte, Cristina Bosco, Alessandro Mazzei (Università di Torino, 2017)
Topic: Lexical and Semantic Resources and Analysis

Abstract
This paper describes a theoretical and empirical investigation about the position of adjectives in the Italian language. The long term goal which oriented the study is the formalization of this information into a natural language generation system. Providing that adjectives mainly occur within noun phrases, we focused on them and we collected data from corpora representing very different text genres, i.e. social media and standard ones, in order to compare the theoretical predictions with the real use of the adjective in Italian. The results obtained by confirm the previsions of the modern linguistic theories but also show the different behaviour of adjectives in the distinct analysed genres.

Introduction
Corpus linguistics is a methodological approach based on the extraction from a set of texts of data useful for the study of language. Even if in principle any collection of texts can be called corpus, the term assumes a more precise connotation in the context of modern linguistics, where a corpus is featured by sampling, representativeness, finite size, machine-readable form and a standard reference AUTHOR. In this work we have applied a corpus-based approach and we considered two different corpora which represent two different text genres: one concerning social media language (PoSTWITA corpus) and one concerning balanced standard Italian (UD-it corpus). Indeed, while social media texts have recently gained great attention from the NLP community since they have many peculiar properties, standard texts can give a more accurate view on the status of some linguistic notions in ``traditional'' written text. These above mentioned corpora allowed us an in depth investigation about the position of the adjective in the nominal phrase. Indeed, even if this grammatical category is described in several traditional Italian grammars AUTHOR, its theoretical status is not currently enough formalized to be used within the computational context. A more useful perspective on the behaviour of the adjective is proposed in a recent theoretical study which is focussed on the position of the adjective in Romance languages AUTHOR. This work aims at achieving two major goals. The first is to empirically confirm with the analysis of corpora the theoretical predictions given in AUTHOR. The second goal is instead to provide a representation and classification of Italian adjective category that can be spent within the SimpleNLG-IT AUTHOR, a surface realizer for Italian language.\\ The paper is organized as follows: in Section~sec::theory we review the linguistic literature concerning the position of the adjective within the Italian noun phrase. In Section~sec::corpora, we explain the details of our corpus linguistic investigation. In Section~sec::nlg, we describe the use of the empirical data in the SimpleNLG-IT realizer. Finally, the Section~sec::conclusions closes the paper with conclusions and some pointers to future work.

Conclusion
The paper presents a study about the behaviour of the adjective within the noun phrase. Providing that the qualitative description given by traditional grammars does not allow the definition of a formal model, we considered a recent study that classifies the descriptive adjectives. The long term goal which oriented this study is to contribute to the development of a natural language generation system for Italian featured by a more careful modelling of the behaviour of words within sentence structures.\\ Assuming a corpus-based perspective we tested on two corpora for Italian the tenets of this study. The results confirm and validate the theory thus opening the window for a definition of a formal model that can be exploited in our computational framework. Future work is planned to extend the validation of our model on larger datasets, where a wider variety of adjectives is used and also more complex noun phrase structures are taken into account with respect to the simple \textlessadjective - noun\textgreater or \textlessnoun - adjective\textgreater associations here considered. In particular, providing that more than one adjective can occurs within a noun phrase and can be syntactically linked to a single noun, we intend to investigate on the preference order also in these cases.