Pro-drop and Theories of pro in the Minimalist Program Part 1: Consistent Null Subject Languages and the Pronominal-Agr Hypothesis

Some languages allow for phonetically null arguments in certain environments. Others do not. This phenomenon, known as pro-drop, arose particular interest in the 80s with the theory of Government and Binding (Chomsky 1981) and the advent of a principles and parameters approach to the theory of grammar. One particularly well-studied phenomenon was subject drop in rich agreement, Italian-type languages, where the occurrence of null subjects correlates with a set of other syntactic properties, thus suggesting that the same abstract property is responsible for apparently unrelated syntactic phenomena. This article starts by reviewing the classic Government and Binding (Chomsky 1981) approach to pro-drop, according to which a phonetically null pronominal argument (pro) is an inherently unspecified nominal projection whose features are supplied contextually. In the case of the rich agreement null subject languages, it was assumed that pro's phi-features are identified by Agr. This view is incompatible with the approach to feature theory developed in the Minimalist Program (Chomsky 1995, 2000, 2001) given that, in this theory, the phi- features in T(=Agr) are uninterpretable and thus not specified for a particular value. In Part 1 of this article we concentrate on the family of analyses that propose that what characterizes the null subject languages of the rich agreement type is that the head bearing subject agreement has a nominal specification and valued phi-features; i.e., Agr behaves like a pronoun spelled out as an affix. In particular, we focus on the consequences of such a hypothesis for the cluster of properties associated with the (rich agreement) consistent null subject languages and for a theory of pro.