With many people grammar has a bad name. It is associated with a pedantic insistence on niceties of expression, with pronouncements that some expression is ‘incorrect’ or ‘correct’ (even though nobody seems to know what ‘correctness’ is), and with consulting authorities to find out what we ‘ought’ to say. This view arises from the conception of grammar as a means of regulating behaviour. We start with the assumption that people use language, and then we regard them as misusing it; so we tell them that they ought to be using it differently. It is like rules of etiquette, where we take as our starting point the social occasion to which the rules apply, say a dinner party, and then we state what amounts to good behaviour—or, sometimes, bad behaviour—on such occasions. To look upon grammar in this way is to trivialize it; to take for granted that the language exists, and merely give rules for adjusting the detail.
But this conception overlooks something, and it is something which will enable us to take a very different view of what grammar is. A language cannot be taken for granted; the rules of English do not assume that English already exists and then prescribe how we ought to use it. They actually define what counts as English.
The distinction can be understood by making a comparison with the rules of some game, say tennis. A rule which states the existence, dimensions and markings of the tennis court is not a rule which regulates the playing of an already existing game; it is a rule that, together with other rules, defines the game itself. If you play on a cricket pitch, you could not be said to be playing bad tennis, but simply not playing tennis. The rules do not control the game; they create it. Only the most trivial rules have a controlling effect; the most essential rules have a constituting effect.
In order to write a grammar for some language, then, we must study the realities of people’s language behaviour and give an account of it in terms of some agreed framework of description. This is a very different thing from attempting to influence people’s language behaviour and make them do it ‘better’. The grammar that we write will be an account of the structural and functional principles of the language itself. This is no trivial matter, since the language spoken by a community of speakers is one of the most essential factors in the life of that community. The community could not exist without this means of controlling almost every aspect of its life; and language is no less than that. A grammar, then, is an attempt to describe the system of communication which every normal member of the community ‘possesses’ and which is shared by the community at large. It has both a psychological existence within the individual and a social existence within the community.