ABSTRACT
This chapter describes the empirical data that support the conclusion that preverbal overt subjects and objects have the same syntactic distribution. It provides some interesting evidence that points to the fact that subject agreement has the same morphological structure of an object clitic. Spanish exhibits ellipsis phenomena which differ in several ways from English VP ellipsis. The special properties of subject quantifiers in preverbal position have been taken as evidence for the appearance of the elements in Spec IP, a nonproperly governed position. The reason preverbal subjects behave like preverbal DOs and IOs is, it would seem, related to the fact that the language allows free variation with respect to the position of the subject. Parallel to the analysis of preverbal subjects, DOs and IOs are also associated with a clitic, which in the same fashion is responsible for the satisfaction of case and theta role assignment.
