Competence refers to a speaker’s implicit knowledge of a language, while performance refers to the actual use of language in real situations.
Competence is stable and abstract, whereas performance is variable and influenced by factors such as memory limitations, distractions, and emotions.
Noam Chomsky introduced the competence-performance distinction in his theory of generative grammar.
Competence includes knowledge of syntax, phonology, morphology, and semantics, but performance may show errors due to processing constraints.
Performance errors (such as slips of the tongue or hesitations) do not indicate a lack of competence, as they result from external factors rather than a deficiency in linguistic knowledge.
Competence is idealized and shared by all native speakers, while performance varies from person to person and situation to situation.