The word 'language' has been used in various senses, especially the 'spoken' form or speech and the written form of expression. This causes some confusion. Hence the French-Swiss linguist Ferdinand de Saussure introduced three terms, viz. language, langue and parole, to distinguish between different senses. He regarded 'language' as the faculty of speech or ability to speak, which all human beings possess hereditarily.
There are two aspects of this faculty: 'langue' and parole', the first implying the language system and the second the act of speaking. Langue comprises all aspects and features of a language taken as a whole, that could be found out through an examination of the memories of all the users of language, or 'the sum of word-images stored in the minds of individuals.' The term parole implies the actual, concrete act of speaking on the part of an individual—-a dynamic social activity in a particular time and place. Saussure gave the name 'parole' to the speech-utterances we actually observe whereas he interpreted 'Langue' as something supra-individual, the common possession of all the people who supposed themselves to be 'speaking the same language", and stored in the collective consciousness of all the members of the community. La langue is a repository of signs which each speaker has received from the other speakers of the community. Wilkins says:
“If one took away what was idiosyncratic or innovational, langue would remain. Langue, by definition, is stable and systematic; society conveys the regularities of langue to the child so that he becomes able to function as a member of the speech community”
The famous American linguist Noam Chomsky first used these terms to specifically refer to a person’s intuitive knowledge of the rules and structure of his language as a native speaker (he called it competence), and his actual use of these (which he termed performance). Scholars of the earlier period were aware of this basic distinction but Chomsky pointed out the inherent ability or knowledge in a native speaker of the structure of his language. It refers to the ability of the native speaker to:
“Understand and produce utterances which he may never find the opportunity either to understand or to produce”
Competence is the tacit knowledge of the language, performance the use of the language in concrete situations. ‘Sentence’ is a concept that belongs to the theory of competence, while ‘utterance’ to performance. The native speaker of a language possesses an ‘internalised set of rules’ which is at the base of his ability to understand and speak. The actual utterances are only evidence of this competence. While reading a new book he sees right from the start new sentences which he had never read before; but he doesn’t find any difficulty in understanding them. His competence also makes him reject the ungrammatical constructions, consider the sentence ‘flying planes can be dangerous’ ambiguous, and ‘I, well, has seen the captain’ wrong. Competence also makes him recognize an expression as command, request etc. Performance is what actually a speaker says. It is the substance, the actual manifestation of his competence. One can understand a speaker’s competence by studying his performance. In learning a new language also it is wiser to develop the basic competence rather than memorise pieces of phrases, as the latter is not a true language behaviour. As Ronald Wardaugh says:
“The ability the reader has to understand novel sentences derives from his competence in English”
Competence vs. Performance given by Chomsky closely resembles the langue/parole dichotomy given by Saussure. But it differs in that while langue is the same with every language user, competence may differ from person to person. Saussure’s understanding of langue emphasizes its predominant social aspect, while Chomsky’s Competence is based on psychology and presumes individual differences between human beings. Thus speaker A may be more competent than B, thought they share the same conventions of language. Similarly A’s Performance would also be different from that of B. Chomsky’s view of competence is also based on the idea of an inbuilt language acquisition device (LAD) in humans what enables a person to acquire competence i.e. to internalize the system of the rules of the language, enabling him to generate the infinite number of sentences. The similarity is that both linguists regard language as a system and ignore the individual speech acts. The notion of langue emphasizes the importance of language as a social phenomenon (Behaviorism). This makes is different from Chomsky’s competence where the tendency is to see language as a biological and genetically inherited faculty (Mentalism); but both the theories see language as an abstract system.