One prediction and one extension derived from Accessibility Theory are explored in response to questions concerning the variable alternation of personal pronominal and null subjects in dialects of Spanish. First, are split antecedents to personal plural subjects informationally inferior to antecedents which are not split? Second, why do the categories of specific and nonspecific second person singular subjects show differing frequencies of null subject expression? With respect to the first question, the answer is no. This contradicts a prediction of Accessibility Theory and calls for a reappraisal of the issue of inferior antecedents. With respect to the second question, the criterion of informativity is extended from its initial scope of specific reference to that of nonspecific reference in order to account for the statistical favoring of pronominal subject expression by nonspecific tú, usted, and uno. However, where Accessibility Theory is unable to account for a favoring of null subjects by nonspecific second person singular tú in Iberian dialects, research from generative treatments of pro arb, provides a basis for, if not explaining, then strongly expecting this particular pattern. Also included, is an analysis of nonspecific second person reference in Latin American dialects which reveals paradigm leveling of the nonspecific tú constraint on subject pronoun expression in the Latin American dialects by analogy to that of nonspecific uno or usted, a direction of change which Accessibility Theory would predict.