Asymmetrical effects of cross-linguistic structural priming on cross-linguistic influence in L2 learners

The present study investigates current proposals that priming is a mechanism of cross-linguistic influence (CLI) in bilinguals by aiming to boost CLI through priming. In two cross-linguistic structural priming experiments with less-proficient adolescent (Study 1) and more highly proficient adult German-English learners (Study 2), we assess whether structural priming enhances CLI for well-formed, dispreferred, and ungrammatical structures. L2 learners in both studies showed CLI in their production, in particular for structures with word order overlap. They also exhibited short-term cross-linguistic priming of grammatical L1-L2 word orders in L2 English, which extended to longer-term priming among the more highly proficient learners in Study 2. However, there was no evidence that cross-linguistic priming increased the use of dispreferred or ungrammatical L1-based word orders in L2 English in either study. Rather, the overall production of these word orders decreased. Together, these results suggest that, while cross-linguistic priming leads learners to increase the use of shared, grammatical L1-L2 word orders, it leads to the inhibition of non-shared ungrammatical structures in L2 production. We conclude that priming has asymmetrical effects on CLI of grammatical and ungrammatical L1-based structures in the L2.