The concept competence originally comes from Chomsky. It refers to the grammatical knowledge of the ideal language user and has nothing to do with the actual use of language in concrete situations. This concept of linguistic competence has been criticized for being too narrow and presenting a "Garden of Eden View". To expand the concept of competence, D. H. Hymes (1971) proposes Communicative Competence which has four components: possibility—the ability to produce grammatical sentences; feasibility—the ability to produce sentences which can be decoded by the human brain; appropriateness—the ability to use correct forms of language in a specific socio-cultural context; performance—the fact that the utterance is completed. Communicative competence includes knowledge of grammar and vocabulary knowledge of rule of speaking, knowledge of how to use and respond to different types of speech acts and social conventions, and knowledge of how to use language appropriately. In Hymes' view, the learner acquires knowledge of sentences not only as grammatical but also as appropriate. i.e. Language learning will successfully take place when language learners know how and when to use the language in various settings and when they have successfully cognized various forms of competence such as grammatical competence (lexis, morphology, syntax and phonology) and pragmatic competence (e.g. speech acts).
The theory of communicative competence stresses the context in which an utterance occurs. In its application, the teacher may teach how in different situations the same sentence can perform the function of statement, command, or request. On the other hand, while introducing different linguistic forms with the same semantic structure, for example the two forms of "you" in Chinese, he may draw special attention to different contexts in which they are used. The conceptual approach also leads to a concentration on discourse, in Hymes‘ term linguistic routines—the sequential organization beyond sentences. Thus in the teaching of literature, the teacher can focus on features of different genres. In the teaching of conversation, he can introduce such strategies as opening, continuing, turn-taking and closing. To present teaching contents of this kind, a learner-centered teaching methodology is necessary.