Optionality in bilingual native grammars

This study investigates the vulnerability of mature native grammars at the interfaces in adult Spanish speakers who have been residing in the US for a mean period of five years but continue to use their L1 on a daily basis. Participants were tested on production and comprehension of subject-verb inversion on two wh-constructions: matrix questions and relative clauses. The crucial distinction between inversion in these two types of constructions is that in relative clauses it is regulated by extra-syntactic conditions such as pragmatic and/or phonological considerations, while inversion in matrix questions is syntactically obligatory. Results showed that pragmatic/phonological inversion is affected by language attrition in the bilingual speakers, whereas purely syntactic inversion remains intact. However, no optionality was found in the comprehension task and no differences in reaction times were attested between monolingual and bilingual speakers.