Abstract
The goal of this study was to use evidence from production data to identify three dimensions along which Japanese children may dis criminate transitive from intransitive verbs. The three dimensions are: (1) case marking, (2) locus of change animacy, as indicated by theme animacy, and (3) planning, as indicated by the appropriate use of verb suffixes denoting request, desire, and prohibition. Production data from two Japanese boys were used in cluster analyses that modelled the role of semantic and formal factors in the organization of the children's verb lexicons. The results confirmed that the semantic dimensions of theme animacy and the planning of an action were sufficient to classify children's verbs into transitive and intransitive groups. It is concluded that at a time when these Japanese children did not use case marking for classification, the children had verb lexicons that were already dif ferentiated into transitive and intransitive classes.