A study tested the hypothesis that if, for the 2-year-old, the transitive/intransitive distinction functions to signal differences in the conceptualization of actions, the child's sentence production should show a relationship between sentence frame and (1) locus of change animacy and (2) the child's expectations concerning an action's outcome. Further, if this form-function mapping is part of the grammar of the language, it is hypothesized that the function of the child's sentence frame distinction should resemble the function of the sentence frame distinction in the caregiver language. Data were drawn from transitive and intransitive sentences spoken by the children in the videotaped interactions of 13 mother-child pairs. Only sentences related to a referent action were considered, and mother sentence samples of approximately equal size were used to assess caregiver sentences. Similarities and differences found in the mothers' and children's systems are examined. (MSE)