Subjects, Topics and the Interpretation of Referential pro. An interface approach to the linking of (null) pronouns

In this paper a novel approach to (a subpart of) the null subject parameter is proposed, in which the interpretation of a thematic pro in subject position is crucially dependent on the syntax and discourse properties of Topic constituents. Based on the analysis of spoken corpora and interface considerations, evidence is provided that preverbal ‘subjects’ sit in an A’-position in a null subject language like Italian and that the interpretation of referential null subjects depends on a matching relation (Agree) with a specific type of Topic. In a cartographic approach to discourse functions, this is identified with the Aboutness-shift Topic (Frascarelli and Hinterhölzl 2007) that is merged in the C-domain and is endowed with the edge feature [+aboutness] – an ‘extended EPP feature’. ATopic Criterion is thus proposed that correlates core grammar with discourse requirements and accounts for the syntactic identification of a referential pro. The Avoid Pronoun Principle is reinterpreted as a structural condition that implies the existence of silent Topics.