Inverse probability adaptation effects (the finding that encountering a verb in an unexpected structure increases long-term priming for that structure) have been observed in both L1 and L2 speakers. However, participants in these studies all had established representations of the syntactic structures to be primed. It therefore remains an open question whether inverse probability adaptation effects could take place with newly encountered L2 structures. In a pre-registered experiment, we exposed participants (n = 84) to an artificial language with active and passive constructions. Training on Day 1 established expectations for specific co-occurrence patterns between verbs and structures. On Day 2, established patterns were violated for the surprisal group (n = 42), but not for the control group (n = 42). We observed no immediate priming effects from exposure to high-surprisal items. On Day 3, however, we observed an effect of input variation on comprehension of verb meaning in an auditory grammaticality judgment task. The surprisal group showed higher accuracy for passive structures in both tasks, suggesting that experiencing variation during learning had promoted the recognition of optionality in the target language.

Native language (L1) processing draws on implicit expectations. An open question is whether non-native learners of a second language (L2) similarly draw on expectations, and whether these expectations are based on learners’ L1 or L2 knowledge. We approach this question by studying inverse preference effects on lexical encoding. L1 and L2 speakers of Spanish described motion events, while they were either primed to express path, manner, or neither. In line with other work, we find that L1 speakers adapted more strongly after primes that are unexpected in their L1. For L2 speakers, adaptation depended on their L2 proficiency: The least proficient speakers exhibited the inverse preference effect on adaptation based on what was unexpected in their L1; but the more proficient speakers were, the more they exhibited inverse preference effects based on what was unexpected in the L2. We discuss implications for L1 transfer and L2 acquisition.

Native speakers show rapid adjustment of their processing strategies and preferences on the basis of the structures they have recently encountered. The present study investigated the nature of priming and adaptation in second-language (L2) speakers and, more specifically, whether similar mechanisms underlie L2 and native language adaptation. Native English speakers and Korean L2 learners of English completed a written priming study probing the use of double object and prepositional phrase datives. Both groups showed cumulative adaptation effects for both types of dative, which was stronger for the structure that was initially less frequent to them (prepositional phrase datives for the native English speakers, and double object datives for the L2 learners). This supports models of priming that incorporate frequency-based modulation of long-lasting activation of structures. L2 learners and native speakers use similar processing mechanisms; differences in adaptation can be accounted for by differences in the relative frequency of structures.