Error-based implicit learning models (e.g., Chang, Dell, & Bock, 2006) propose that a single learning mechanism underlies immediate and long-term effects of experience on children's syntax. We test two key predictions of these models: That individual experiences of infrequent structures should yield both immediate and long-term facilitation, and that such learning should be consistent in individual speakers across time. Children (and adults) described transitive events in two picture-matching games, held a week apart. In both sessions, the experimenter's immediately preceding syntax (active vs. passive) dynamically influenced children's (and adults') syntactic choices in an individually consistent manner. Moreover, children showed long-term facilitation, through an increased likelihood to produce passives in Session 2, with speakers who were most likely to immediately repeat passives in Session 1 being most likely to produce passives in Session 2. Our results are consistent with an error-based syntactic learning mechanism that operates across the lifespan.

Children recruit verb syntax to guide verb interpretation. We asked whether 22-month-olds spontaneously encode information about a particular novel verb’s syntactic properties through listening to sentences, retain this information in long-term memory over a filled delay, and retrieve it to guide interpretation upon hearing the same novel verb again. Children watched dialogues in which interlocutors discussed unseen events using a novel verb in transitive (e.g., “Anna blicked the baby”) or intransitive sentences (“Anna blicked”). Children later heard the verb in isolation (“Find blicking!”) while viewing a two-participant causal action and a one-participant action event. Children who had heard transitive dialogues looked longer at the two-participant event than did those who heard intransitive dialogues. This effect disappeared if children heard a different novel verb at test (“Find kradding!”). These findings implicate a role for distributional learning in early verb learning: syntactic-combinatorial information about otherwise unknown words may pervade the toddler’s lexicon, guiding later word interpretation.

We examined whether input modality and individual differences in attention and motivation influence second language (L2) learning via syntactic priming. In an online study, we compared the primed production of English passives by 235 L2 and native English speakers in reading‐to‐writing versus listening‐to‐writing conditions. We measured immediate priming (producing passives immediately after exposure to passives) and short‐ and long‐term learning (producing more passives in immediate and 1‐week delayed posttests relative to pretests). Both groups showed immediate priming and short‐ and long‐term learning, although L2 speakers produced more passives with immediate priming and showed greater long‐term learning. Learning was unaffected by modality, but immediate priming was greatest in the listening‐to‐writing condition across groups. Individual differences in attention and motivation did not influence priming or learning. Thus, syntactic priming fosters long‐term L2 learning regardless of input modality, but participants may be sensitive to the frequency of passives in spoken versus written language during immediate priming.