An oral screening test administered by an adult to a five-year-old child was transcribed and analyzed. The test was chosen as an example of a referential communication task that is also a social communication task. The analysis demonstrates that a participant in communication assumes that the other participants are employing strategies for inferring social meaning, and that a failure of two participants' inferences to match results in a "stumbling" and a misunderstanding even on the literal, referential level. In the case of the screening test, one result of misunderstandings is that the child's overall score is different from what it would have been had she been more skilled in interpreting the social meaning of talk. A key aspect of processes of conversational inference and interpersonal coordination is shown to be the timing of interaction. Behavioral means by which communication is socially and rhythmically organized are discussed, with reference to the development of these means as an aspect of child language acquisition. (JB)