We have already considered two levels of description used in the study of language. We have described linguistic expressions as sequences of sounds that can be represented in the phonetic alphabet and described in terms of their features.

We can take the same expression and describe it as a sequence of morphemes.

With these descriptions, we could characterize all the words and phrases of a language in terms of their phonology and morphology

However, we have not accounted for the fact that these words can only be combined in a limited number of patterns. We recognize that the phrase the lucky boys is a well formed phrase in English, but that the following two “phrases” are not at all well formed.

(We use an asterisk * to indicate that a form is unacceptable or ungrammatical.) From these examples, we can see that English has strict rules for combining words into phrases. The article (the) must go before the adjective (lucky), which must go before the noun (boys). So, in order to be grammatical, this type of phrase must have the sequence article + adjective + noun (and not *noun + article + adjective, for example).

The process of describing the structure of phrases and sentences in such a way that we account for all the grammatical sequences in a language and rule out all the ungrammatical sequences is one way of defining grammar. It is the kind of definition assumed when we talk about the grammar of English as opposed to the grammar of Swahili, Tagalog or Turkish. As illustrated in Chapter 6, each of these languages has different ways of forming grammatical phrases and sentences. Studying grammar in this way has a very long tradition.