Children's understanding of the grammatical categories of "determiner" and "adjective" was examined using 2 different methodologies. In Experiment 1, children heard novel nouns combined with either a or the. Few 2-year-olds, but nearly all 3- and 4-year-olds, subsequently produced the novel nouns with a different determiner from the modeled combination. Experiment 2 used a priming methodology. Children age 2, 3, 4, and 6 years repeated descriptions of pictures, before describing target pictures themselves. When the primes consisted of a varied determiner + noun, all age groups produced more determiner + noun descriptions. When the primes consisted of a determiner + adjective + noun, 2-year-olds showed no priming. Three- to 6-year-olds showed item-specific priming, but only 6-year-olds (and to a limited extent 4-year-olds) showed both item-specific and structural priming. These results suggest that children build an understanding of determiners and adjectives gradually, perhaps from individual lexical items, over a number of years, and that pragmatic correctness may be attained particularly late.