Résumé
In this paper we analyse the clause structure of old Italo-Romance, which, departing from late Latin, is characterized by a ‘verb-second’ (V2) syntax, typical of the medieval languages. In particular, we focus on Subject and Object, showing how the syntactic distribution of these two grammatical relations is sensitive to discourse function, and interfaces with pragmatic conditions (Focus, Aboutness Topic, Referential Topic) and semantic properties (definiteness, specificity, identifiability) in the information structure. As for the Subject, we observe how the tension between the definiteness of the referent, on the one hand, and the ‘new’, non-presupposed information value, on the other hand, determines free variation between pre- and post-verbal position. This tension is less prominent in old Sicilian, where the ‘thematization’ of the Subject in first position is no longer restricted to Aboutness Topics, but is extended also to Referential Topics, thus anticipating the [SVO] order of Modern Italian. As for the Object, we document the emergence of resumptive clitics, which first appear in contexts in which the dislocated Object is a Referential Topic, and only later are they generalized also to Aboutness Topics, as is the case with Modern Italian.