Abstract: The present study explores two questions: What is the nature of older children’s syntactic knowledge; how is that knowledge used in an everyday speech situation? Six-, eight-, and ten-year-olds repeated grammatical sentences as read by the first experimenter. Half the sentences were syntactically clear, half slightly distorted. Clear versions displayed basic grammatical relations and constituent structure perspicuously. The second experimenter, who sat at the other end of the room, asked “what?” after each sentence. The syntactic changes children might make to accommodate the listener were examined. Although the children made a variety of changes, at all ages they tended to change distorted versions to clear ones, and to repeat clear versions. The results suggest that children’s syntactic knowledge is deeper and more accessible than had been supposed.