Does syntax guide semantic predictions in L1 and L2 processing?

In two visual world experiments with L1 and L2 German speakers, this study investigates how listeners use semantic cues on the verb to predict either a post-verbal object in subject-first SVO sentences or a post-verbal subject in adverb-first verb-second (AdvVS(O)) sentences, with the goal of assessing to what extent the syntax of an unfolding sentence constrains the activation of potential upcoming referents. In all sentence types, both L1 and L2 listeners looked at the referent of the post-verbal argument earlier when the verb was semantically constraining than when it was not. Predictive looks were slower overall in the L2 group, but not attenuated in syntactic configurations absent from their L1, namely, adverb-first verb-second (AdvVS(O)) sentences. Both groups were more likely to fixate plausible subjects than objects on hearing a transitive verb following a sentence-initial adverb, suggesting that prediction of an upcoming argument was constrained not only by semantic association with the verb, but also by the syntactic and thematic structure of the unfolding sentence. These results underscore how sentence-level cues, like word order and the distribution of grammatical and thematic roles, can guide the use of local, namely lexical-level, cues during semantically-cued prediction in both L1 and L2 processing.