COMPETENCE
Chomsky has proposed
(which he has frequently updated) is actually a theory of linguistic competence
. He makes “a fundamental distinction between competence
(the speaker-hearer’s knowledge of his language) 
and performance (the actual use of language in concrete situations)”
linguistic competence
Is the speaker–hearer’s tacit, rather than conscious or even cognitively accessible, knowledge of the language-system.”
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linguistic competence,
subsumes phonological,
syntactic
semantic subsystems.
Linguistic competence entails a semantic component that
indicates the intrinsic meaning of sentences
As Chomsky clarifies,
The notion of competence does not include actual language use: “The term ‘competence’ entered the technical literature in an effort to avoid the slew of problems
relating to ‘knowledge,’ but it is misleading in that it suggests ‘ability’—an
association I would like to sever
Reference: Kumaravadivelu, B. (2008). UNDERSTANDING LANGUAGE TEACHING From Method to Postmethod. San Jose State University. Lawrence Erlbaum Associates, Inc., Publishers. Part 1: Chapter 1, 2 & 3
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