The traditional view of the null subject as pro identified by Agr (the φ-features of I) cannot be maintained in a theory where Agr is uninterpretable. Two hypotheses are compared with regard to the predictions they make for Finnish null subject constructions: (A) Agr is interpretable in null subject languages, and pro is therefore redundant; (B) null subjects are specified but unpronounced pronouns that assign values to the uninterpretable features of Agr. Since Finnish observes the Extended Projection Principle and has an expletive pronoun, Hypothesis A predicts that null subjects should cooccur with expletives. The prediction is false, favoring B over A. A typology of null subjects is proposed: Null bound pronouns and null generic pronouns in partial null subject languages, including Finnish, are D-less φ, and so are null subjects in consistent null subject languages with Agr, such as Spanish and Greek. Null 1st and 2nd person subjects in Finnish are DPs that are deleted. Null pronouns in languages without Agr, such as Chinese and Japanese, are the only true instances of pro, a minimally specified null noun.