Toddlers exploit referential and syntactic cues to flexibly adapt their interpretation of novel verb meanings.

Because linguistic communication is often noisy and uncertain, adults flexibly rely on different information sources during sentence processing. We tested whether toddlers engage in a similar process and how that process interacts with verb learning. Across two experiments, we presented French 28-month-olds with right-dislocated sentences featuring a novel verb ("He is VERBing, the boy"), where a clear prosodic boundary after the verb indicates that the sentence is intransitive (such that the NP "the boy" is coreferential with the pronoun "he" and the sentence means "The boy is VERBing"). By default, toddlers incorrectly interpreted the sentence based on the number of NPs (assuming, e.g., that someone is VERBing the boy). Yet, when children were provided with additional information about the syntactic contexts (Experiment 1, N = 81) or the referential/semantic content (Experiment 2, N = 72) of the novel verb, they successfully used the prosodic information as a cue to reach the correct syntactic structure of the sentence and infer the probable meaning of the novel verb. These results suggest that toddlers can flexibly adjust their interpretations of sentences depending on the reliability of the linguistic cues available. Thus, failure to parse a sentence in an adult-like fashion might not necessarily reflect the immaturity of children's parsing system but rather might be indicative of what cues children consider reliable in that context.