Null Subjects in Early Child English and the Theory of Economy of Projection

In this paper, we present new evidence showing that some of the empty subjects produced by young children acquiring English cannot be subsumed under the performance limitation analysis of Bloom (1990) or the Topic-drop analysis of Rizzi (1994). We argue contra Sano & Hyams (1994) that these missing subjects are instances of pro, not PRO, and demonstrate that the economy-based pro-drop theory of Speas (1994) handles our data in an elegant fashion. The analysis we propose links the acquisition of subjects to the acquisition of functional morphology, in accordance with the minimalist program developed since Chomsky (1989). One desirable consequence of the approach taken here is that no recourse to a pro-drop parameter is necessary.