Abstract
Two experiments showed that 2.5‐year‐olds, as well as older children, interpret new verbs in accord with their number of arguments. When interpreting new verbs describing the same motion events, children who heard transitive sentences were more likely than were children who heard intransitive sentences to assume that the verb referred to the actions of the causal agent. The sentences were designed so that only the number of noun‐phrase arguments differed across conditions (e.g.She’s pilking her over thereversusShe’s pilking over there). These experiments isolate number of noun‐phrase arguments (or number of nouns) as an early constraint on sentence interpretation and verb learning, and provide strong evidence that children as young as 2.5 years of age attend to a sentence’s overall structure in interpreting it.