Different registers, different grammars? Subject expression in English conversation and narrative

As a so-called non-null subject language, it has been proposed that in English, unexpressed subjects occur only in registers that have specific grammatical properties. We test this hypothesis through a comparison of the conditioning of subject expression for third-person singular human specific subjects in English conversation and narrative. Despite a stark difference in the rates of nonexpression (4% in conversation vs. 22% in narratives), there is no evidence of different grammars across the registers-in both, outside of coreferential clauses conjoined with a coordinating conjunction, unexpressed subjects only occur in prosodic initial position in main clause declaratives. Within the variable context, in both registers, expression is sensitive to accessibility, priming, and temporal sequentiality. A register effect is, however, evident in the contextual distribution, with a larger proportion of the narrative tokens occurring in contexts propitious to unexpressed subjects, and it is this that accounts for the higher rate of nonexpression in this register.