On the diachronic reanalysis of null subjects and null objects in Brazilian Portuguese

This paper discusses some acquisition issues involved in the syntactic changes that affected the distribution and interpretation of null subjects and null objects in Brazilian Portuguese (BP). Based on work by Ferreira (2000) and Nunes (2008a), I argue that the emergence of finite control in BP was triggered by the weakening of its verbal agreement paradigm associated with the fact that some infinitival forms are ambiguous in being associated with a complete or an incomplete set of φ-features. As for null objects, I discuss some consequences of Nunes’s (1993) proposal that the appearance of pronominal null objects in BP was ultimately a by-product of the change in the directionality of phonological cliticization in the language.