According to Hartsuiker et al.'s (2004) shared-syntax account bilinguals share syntactic representations across languages whenever these representations are similar enough. But how does such a system develop in the course of second language (L2) learning? We will review recent work on cross-linguistic structural priming, which considered priming in early second language learners and late second language learners as a function of proficiency. We will then sketch our account of L2 syntactic acquisition. We assume an early phase in which the learner relies on transfer from L1 and imitation, followed by phases in which language- and item-specific syntactic representations are added and in which such representations become increasingly abstract. We argue that structural priming effects in L2 (and between L1 and L2) depend on the structure of this developing network but also on explicit memory processes. We speculate that these memory processes might aid the formation of new representations.
