flesl.net grammar glossary::grammatical form and function

grammatical form and function

• The basic goal of grammar is to provide an understanding of the sentence — the topmost element of the grammatical hierarchy. However, the idea of a sentence is not entirely clear-cut and defineable; for one thing, it is often difficult to say where one sentence ends and another begins. Because of this, it is best to begin doing basic grammar with a consideration of the next lower member of the hierarchy, the clause, and at a further point, to base an explanation of sentences on a prior understanding of clauses.

• It is important to keep in mind when considering this matter, that because of the possibility of immediate constituency a sentence can be, and often is, made up of only one clause. Such sentences — they are called “simple sentences” — can be said, quite accurately to be clauses as well as being sentences.

• In order to understand clauses, it is necessary to distinguish between grammatical function and grammatical form. The basic idea is this: the five types of clause constituent — subjects, verbs, objects, complements and adverbials — are functionally defined. A subject, for example, is a subject because of the role it plays in a clause — because of how it functions in other words. However, with one exception, the verb, each of these functions can be fulfilled by different forms (or “structures”). The subject and object function can fulfilled by pronouns, noun phrases or noun clauses. The function of complements can be fuilfilled by noun phrases or adjective phrases. The adverbial function can be fulfilled by adverb phrases, prepositional phrases, and adverbial clauses. (see examples below). As was mentioned above, the verb function can be fulfilled by only one form: the verb phrase.

• example of various fulfillments of the adverbial function

the adverbial function is fulfilled by an adverb phrase ——  Tom is writing the report very quickly.  

the adverbial function is fulfilled by a prepositional phrase —— Tom works in a library.

the adverbial function is fulfilled by an adverbial clause ——Tom works when he can find a job.

• The straightforward possibility of a function being fulfilled by more than one structure is not the only reason for the importance of this distinction. It is also useful as a way of dealing with the fact that adverbials, unlike other clause elements, are often mobile. For example, in the first of the three examples above the adverbial phrase can quite easily be placed between the auxiliary verb and the main verb: Tom is very quickly writing the report. However, an adverbial clause like, when he has the time, cannot be substituted when the adverbial is in that position although it can be substitued when the adverbial comes at the end of the clause. This difference can be expressed by saying that in the context, S + Aux + V + O, an adverbial that is fulfilled by a adverb phrase can be placed between the auxiliary and the main verb but an adverbial that is fulfilled by an adverbial clause cannot be so placed.