Subject pronouns in Spanish-English code-switching

While the Minimalist Program argues that Spanish-English code-switches between pronominal subjects and finite verbs are ungrammatical (Van Gelderen & MacSwan, 2008), the MLF/4-M models (Myers-Scotton, 1993; Myers-Scotton & Jake, 2000) predict their grammaticality when overt pronouns are obligatory in both languages (e.g., contrastive focus). In this study, we test the contrary predictions of these models using a code-switching production task. Thirty-eight Spanish-English bilinguals (31 female; Age: 18–23 years) completed a concurrent memory-loaded repetition task where visual primes forced broad or contrastive focus interpretations. We also examined the effects of switch direction, code-switching frequency, and language dominance. The results showed that code-switches between a Spanish overt pronoun and an English inflected verb were more accurately produced in the contrastive focus than the broad focus condition, lending support for the MLF/4-M models. No effect of code-switching frequency was found. Finally, higher Spanish dominance resulted in more accurate production of these code-switches.