Definitions of communicative competence and research on developing communicative competence in a second language are reviewed and implications for teaching are discussed. Communicative competence refers not only to knowledge of the forms of a language but to their functions and appropriate use in context. Five areas of communicative competence are identified: linguistic rules, speech acts, propositional content, interactional patterns, and strategic competence. The research in each of these areas is reviewed. Ten general instructional principles derived from the research are offered that focus on such factors as use of polite forms, practice with communicative strategies, opportunity to use the language, error analysis and correction, understanding of the students' reasons for learning the language, and the teacher's enthusiasm for the language. In conclusion, teachers should attempt to communicate their enthusiasm while understanding the realistic limitations of their task of teaching a second language. References are appended. (RW)