The evolution of the concept of communicative competence (CC) in language learning and teaching is traced since 1966, when D. H. Hymes first discussed it publicly. His concept of CC had its theoretical origins in the convergence of transformational generative grammar and the ethnography of communication, and was first discussed at a conference on language development among disadvantaged children with the implication that "sociolinguistic interference" might be more important for education than dialect differences. Hymes defines competence as capability located in individual persons, and translates Noam Chomsky's concept of underlying shared knowledge as "systemic potential." He distinguished between what is not said because there is no need to say it and what is not said because the individual does not have a way to say it. Competence is viewed as an individual quality, including knowledge of a formal grammatical structure and also knowledge of form/function relationships (appropriateness). The issue of defining appropriateness for pedagogical purposes has stimulated discussion, but in keeping with the contemporary emphasis on the active role of the learner, a definition focusing on the learner's grasp of language for use is gaining ground. Contains 13 references. (MSE)