The nature of grammar as a constituent part of language

The nature of grammar as a constituent part of language is better understood in the light of explicitly discriminating the two planes of language, namely, the plane of content and the plane of expression.

The plane of content comprises the purely semantic elements contained in language, while the plane of expression comprises the material (formal) units of language taken by themselves, apart from the meanings rendered by them. The two planes are inseparably connected, so that no meaning can be realised without some material means of expression. Grammatical elements of language present a unity of content and expression (or, in somewhat more familiar terms, a unity of form and meaning). In this the grammatical elements are similar to the lingual lexical elements, though the quality of grammatical meanings, as we have stated above, is different in principle from the quality of lexical meanings.

On the other hand, the correspondence between the planes of content and expression is very complex, and it is peculiar to each language. This complexity is clearly illustrated by the phenomena of polysemy, homonymy, and synonymy.

In cases of polysemy and homonymy, two or more units of the plane of content correspond to one unit of the plane of expression. For instance, the verbal form of the present indefinite (one unit in the plane of expression) polysemantically renders the grammatical meanings of habitual action, action at the pre-sent moment, action taken as a general truth (several units in the plane of content). The morphemic material element -s/-es (in pronunciation [-s, -z, -iz]), i.e. one unit in the plane of expression (in so far as the functional semantics of the elements is common to all of them indiscriminately), homonymically renders the grammatical meanings of the third person singular of the verbal present tense, the plural of the noun, the possessive form of the noun, i.e. several units of the plane of content.

In cases of synonymy, conversely, two or more units of the plane of expression correspond to one unit of the plane of content. For instance, the forms of the verbal future indefinite, future continuous, and present continuous (several units in the plane of expression) can in certain contexts synonymically render the meaning of a future action (one unit in the plane of content).

Taking into consideration the discrimination between the two planes, we may say that the purpose of grammar as a linguistic discipline is, in the long run, to disclose and formulate the regularities of the correspondence between the plane of content and the plane of expression in the formation of utterances out of the stocks of words as part of the process of speech production.