ABSTRACT
Developments in children's early vocabulary acquisition should be intimately connected to developments in their communicative abilities. Although at the level of identifying the communicative intent underlying utterances both interchange type and speech act were coded for, at further stages of analysis some of the detailed communicative act categories were combined on theoretical grounds. Utterances were related to the intent assumed to have generated them in order to discover the principle by which the intent may be recoverable from what was said. Unless children possess enough communicative competence to decode the social meaning packaged into an unknown expression, they cannot learn the meaning of that expression. The children's vocabularies at each observation were separated into their single-word vocabulary—namely, words used in single-word utterances—and their multiword vocabulary—namely, words used exclusively in multiword utterances. Single-word utterances were coded for the type of social-communicative act performed in uttering the utterance, using a detailed category system developed in the study.
