Diachronic aspects of the argument structure of sentences with “trata-se de”

Abstract

This paper reports on the results of a diachronic corpus-based research into the different usages of trata-se de in Portuguese, focusing on changes in its argument structure. Through a data analysis based on the Multisystemic Approach to Language, the research supports the hypothesis that the specialization of usages of the non-full verb tratar in this structure (impersonal presentational sentences and identificational sentences with external argument) is associated with the concealment of thematic functions produced by the clitic se in several types of sentences throughout the history of Portuguese, a phenomenon known as dethematization. The data used in the research was obtained from the Corpus of Portuguese and was located with its search engine.