Romance Null Subjects at the Sensory-Motor Interface

This paper reevaluates approaches that attempt to explain the properties of null subjects in Romance null-subject languages (NSLs) by appealing to the parameterized existence of a lexical entry of a null pronominal category, namely, pro. I propose instead that the fact that these languages allow null subjects in finite-clause contexts can be deduced from other properties of their grammars, and so it need not be lexically stipulated. I show that within a derivational approach without look-ahead, the theoretical apparatus needed to generate further-raising (A-movement after Spec-head agreement with a φ-complete Tense), a phenomenon that is found in Romance NSLs, automatically generates null subjects as well. I will then account for the thus-far-unexplained correlation that if a language allows further-raising it also allows null subjects. I first argue that the operation of Agree is parameterized with respect to Case feature valuation. Then I argue that, given this parametric difference, the phonological features of DPs in Romance NSLs can remain uninterpretable at the Sensory-Motor Interface, yielding the surface effect of a null subject, under certain assumptions about Case and its role in the derivation and about the interpretation of phonological features at the Sensory-Motor Interface.