Revision behaviors in the speech of normal children were investigated. The subjects were 18 children, six at Brown's Language Stages I, II, and III. During the collection of a one-hour spontaneous language sample from each child the experimenter pretended 20 times not to understand and asked, "What?" The results indicate a significnatly greater use of revisions than repetitions or no responses at each stage and significant differences among the types of revisions observed across stages. These findings are related to current language models.