Aims
The main aims of linguistic prescription are to define standardised language forms either generally (what is Standard English?) or for specific purposes (what style and register is appropriate in, for example, a legal brief?) and to formulate these in such a way as to make them easily taught or learned.[citation needed] Prescription can apply to most aspects of language: to spelling, grammar, semantics, pronunciation and register. Most people would subscribe to the consensus that in all of these areas it is meaningful to describe some kinds of aberrations as incorrect, or at least as inappropriate in formal contexts. Prescription aims to draw workable guidelines for language users seeking advice in such matters.

Standardised languages are useful for interregional communication; speakers of divergent dialects may understand a standard language used in broadcasting more readily than they would understand each other's. One can argue that such a lingua franca, if needed, will evolve by itself, but the desire to formulate and define it is very widespread in most parts of the world. Writers or communicators who wish to use words clearly, powerfully or effectively often use prescriptive rules, believing that these may make their communications more widely understood and unambiguous. The vast popularity of books providing advice on such matters shows that prescription meets a real, or at least widely perceived need.[citation needed]