Usage patterns for common nouns continue to change well past the early years of language acquisition in free naming (Andersen, 1975; Ameel, Malt, & Storms, 2008). The current research evaluates whether this continued evolution is shown in receptive judgments as well, given their differing cognitive demands. We found an extended learning trajectory for children aged 7-13 years old. In contrast to the over- and underextensions found in Ameel et al.'s free-naming task, however, only overextensions were found. Children's lexical categories showed initial overlap, but with age the overlap gradually disappeared and the categories became more distinct. The cognitive demands of production influence the particular deviations from adult usage that appear in free naming, but even for receptive competence, acquiring full adult word knowledge and the ability to use it in different ways is a lengthy process that requires acquisition and consolidation of knowledge at multiple levels.