This paper reports on two aspects of dyadic communication skills: verbal imitation, and response to questions and commands, as they relate to the development of semantic functions in three English-speaking children. The children, aged 16, 21 and 22 months, were unobtrusively videotaped during weekly free play sessions with their mothers. The videotapes were completely transcribed and then coded along three dimensions: action context, communicative interaction, and semantic function. The situations reported on here (imitation, and response to questions and commands) are categories on the communicative interaction dimension. It is hypothesized that verbal imitation performs an important communicative function, so the first question concerned the kinds of words children imitated. This was answered in three ways: (1) with respect to the word's position in the adult sentence, (2) with respect to the part of speech, and (3) with respect to the semantic function. A second means by which children indicate communicative skills is by appropriately answering questions and commands. The three children in this study displayed evidence that they were beginning to process questions and commands as a special kind of verbal input, particularly in the development of answers to yes/no questions and naming questions. (AMH)