Reanalyzing production data from 3 French children, we make 2 basic points. First, we show that tense and agreement inflection follow independent courses of acquisition (in child French). Tense production starts and ends at near-adult levels but suffers a "dip" in production in the intermediate stage. Agreement develops linearly, going roughly from none to 100% over the same time. This profile suggests an analysis in which tense and agreement compete at the intermediate stage. Second, using a mechanism of grammatical development based on partial rankings of constraints (in terms of Optimality Theory; Prince and Smolensky (1993)), our analysis successfully models, over 3 stages, the frequency with which children use tensed, agreeing, and nonfinite verbs.