We use a comparative variationist framework to compare variable word-final obstruent devoicing patterns in heritage Polish, English and homeland Polish in conversational speech. Phonological and lexical factors are shown to condition this variation differently in the three varieties. We have a particular interest in one other factor relevant to heritage speakers: the amount of code-switching between Polish and English by each speaker. We show that, for second generation heritage speakers, individuals' code-switching rates are positively correlated with their rates of devoicing. Based on the qualitatively and quantitatively different devoicing patterns of heritage Polish speakers, compared to both homeland Polish and Toronto English, we argue that the phonological grammar of this group of speakers constitutes a convergence of the heritage language and the dominant language's grammars and suggest that frequent code-switching provides the context in which these speakers' knowledge of Polish and English patterns converge.
Keywords: Polish, language contact, variationist sociolinguistics, phonological variation, devoicing