Competence and Performance

Linguistic Competence

In generative grammar, competence is then taken to represent the underlying knowledge a pheno- and neurotypical human adult has of his or her native language. In this way, it is an instantiation of universal grammar (UG), which can be thought of, along with non-language-specific factors, as determining the initial state of language acquisition.

Consequently, adult competence is partly determined by, but also distinct from, UG. Concretely, linguistic competence can be considered “grammatical competence,” to include knowledge of words, knowledge of grammatical symbols necessary for assessment by an evaluation metric, and knowledge of parts of speech, for example. This view assumes the human capacity for underlying, tacit linguistic knowledge unique to the species; in biolinguistics, the shorthand UG is typically employed to designate both the biological human capacity for grammatical knowledge itself and the theory of that capacity that linguists are trying to construct.

This “generative grammar–biolinguistic amalgam” aims to account for the discrepancy from well-known biological investigations between the paucity of information available to an organism from its environment and the complexity of the structures it develops. The argument from poverty of the stimulus holds that linguistic competence is radically underdetermined by the data to which a language acquirer is exposed: Infinitely many systems are consistent with a finite dataset yet are inconsistent with one another.

Given the speed and accuracy with which language acquirers converge on grammatical systems despite this insufficient and widely varying input, whatever is responsible must be biased or constrained in certain ways to be able to account for it. A rich innate grammatical competence as part of the human faculty of language is motivated by this need for explanatory adequacy.

Linguistic Performance

In contrast to competence, linguistic performance is arguably not a well-defined notion; basically, all aspects of speech production and comprehension, and perhaps even making judgments on grammaticality, well-formedness, or acceptability, that do not reflect the grammar are called performance. In the literature, discussions of performance are typically concerned only with so-called performance errors—situations in which the performance systems appear to obscure the grammatical output (e.g., the aforementioned memory limitations, distractions, or production errors such as slips of the tongue).

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