Two languages, one effect: Structural priming in spontaneous code-switching

We investigate here the contribution of code-switching and structural priming to variable expression of the Spanish first person singular subject pronoun in the New Mexican bilingual community. Comparisons with both Spanish and English benchmarks indicate no convergence of Spanish toward English grammar, including in the presence of code-switching, where the linguistic conditioning of variant selection remains unaltered. We find a language-internal and cross-language priming effect, albeit of differing strength, such that speakers' preceding coreferential (Spanish and English) subject pronouns favor subsequent pronouns, whereas unexpressed subjects tend to be followed by unexpressed subjects. Given the rarity of unexpressed subjects in English, in the presence of code-switching fewer tokens occur with unexpressed primes. Thus, code-switching has no intrinsic effect. Instead, it results in associated shifts in the distribution of contextual features relevant to priming, contrary to the convergence-via-code-switching hypothesis and in accordance with the contextual distribution-via-code-switching hypothesis, which we put forward here.