Prosody, priming and particular constructions: The patterning of English first-person singular subject expression in conversation

Unexpressed subjects, though rare, do occur systematically in English. In this study, we seek to answer the question of what motivates speaker choice between expressed and unexpressed first singular subjects (i.e. I vs. an unexpressed, or null, pronoun) in a corpus of conversational American English. We find that the apparently widespread cross-linguistic constraint of subject continuity is bound to coreferential coordinating constructions with and, including lexically particular constructions ([I Verb_1sgi and Ø Quotative verb_1sgi], [I go_1sgi and Ø Verb_1sgi]), and to an overarching priming constraint, whereby coreferential unexpressed mentions tend to cluster together. A pivotal restriction is prosodic, such that, outside of coordinating constructions, unexpressed 1sg subjects occur only in Intonation-Unit initial position. We therefore find that variable I expression is sensitive to factors operative in subject expression in other languages and in language variation more generally, though paramount are prosodic considerations and particular constructions that may be specific to English.