Although intonation has been said to be one of the first meaningful units of language that a child acquires, it is difficult to say just what this really means. How does the child learn to distinguish the various grammatical meanings that an intonation can have? It was hypothesized that the child first acquires question and request forms on the basis of intonation contours, but gradually comes to recognize other linguistic markers (illocutionary markers) marking the sentence to be a question or a request. At a later stage of development, therefore, the hypothesis was that the child will answer questions and requests even if the intonation contour did not by itself denote the utterance to be a question or request, as long as there were other markers present to signify to the child that the utterance was a question or request. It was also hypothesized that the adult also uses more intonation-determined questions to the child at a younger age than at an older age. The results support these hypotheses. (Author/CLK)