The shared-syntax account of bilingual syntactic representations suggests that similar structures from different languages are represented as one in the bilingual mind. In this study, we examined the degree of morpho-syntactic similarity needed for representations to be shared in the bilingual mind by comparing passive structures in Greek and English. Contrary to English, non-active morphology in Greek is not restricted to passives and the “by phrase” is considered marked. In two structural priming experiments, we examined whether passives can be primed in L1-Greek and, subsequently, whether there is a single representation for passives in Greek–English bilinguals despite distributional and morpho-syntactic differences. Results showed that passive structures were primed in L1-Greek (Experiment 1) and from L1-Greek to L2-English (Experiment 2). Our findings suggest that morpho-syntactic and distributional differences inherent to passives do not prevent priming, and that structural representations can be shared even when featural structure is not identical.

In this review, we examine how structural priming has been used to investigate the representation of first and second language syntactic structures in bilinguals. Most experiments suggest that structures that are identical in the first and second language have a single, shared mental representation. The results from structures that are similar but not fully identical are less clear, but they may be explained by assuming that first and second language representations are merely connected rather than fully shared. Some research has also used structural priming to investigate the representation of cognate words. We will also consider whether cross-linguistic structural priming taps into long-term implicit learning effects. Finally, we discuss recent research that has investigated how second language syntactic representations develop as learners’ proficiency increases.