We will see that there is considerable variation in the speech of any one individual, but there are also definite bounds to that variation: no individual is free to do just exactly what he or she pleases so far as language is concerned. You cannot pronounce words any way you please, inflect or not inflect words such as nouns and verbs arbitrarily, or make drastic alterations in word order in sentences as the mood suits you. If you do any or all of these things, the results will be unacceptable, even gibberish. The variation you are permitted has limits and these limits can be described with considerable accuracy. Individuals know the various limits (or norms), and that knowledge is both very precise and at the same time almost entirely unconscious. It is also difficult to explain how individual speakers acquire knowledge of these norms of linguistic behavior, for they appear to be much more subtle than the norms that apply to such matters as social behavior, dress, and table manners.
Today, most linguists agree that the knowledge speakers have of the language or languages they speak is knowledge of something quite abstract. It is a knowledge of rules and principles and of the ways of saying and doing things with sounds, words, and sentences, rather than just knowledge of specific sounds, words, and sentences. It is knowing what is in the language and what is not; it is knowing the possibilities the language offers and what is impossible. This knowledge explains how it is we can understand sentences we have not heard before and reject others as being ungrammatical, in the sense of not being possible in the language. Communication among people who speak the same language is possible because they share such knowledge, although how it is shared – or even how it is acquired – is not well understood.
In their performance speakers behave systematically: their actions are not random; there is order. Knowing a language also means knowing how to use that language since speakers know not only how to form sentences but also how to use them appropriately. There is therefore another kind of competence, sometimes called communicative competence.
1.5. Methods employed by sociolinguistics
