In §1 we found that that grammar is a system in language which presents meaning through opposition of variants of units. This idea is the basic statement which makes it possible to deduce a great numbers other statements describing already particular features of Grammar of different languages including English. But to understand these statements we should know the meaning of words (or terms) used in them. Those terms are names of the basic notions of this kind of describing Grammar.
The first notion is grammatical meaning. A grammatical meaning differs from any other sort of meaning in four features:
ÞA GRAMMATICAL MEANING IS OPPOSITIVE.
Oppositive character of grammatical meaning is evident in the fact that any grammatical meaning is not only revealed through opposition but cannot simply exist outside of it. If we take such English forms as "must", "ought (to)", "should". "would" or even "could" and "might" we can see that these forms in spite of clear indications of the Past[1] do not actually possess this meaning. Yet due to the feature "obligatory" these forms are treated as ... Present. Adjectives in all Germanic languages but English have the meanings of Gender and Number. English having no forms which can be opposed on these features has none of them. Being oppositive grammatical meanings are relative, which means that they are determined by the system of oppositions in which they are found. We know that some actions which in East Slavonic languages are represented as Past in English are treated as Present: "ß çàáûë, êàê åãåî çîâóò" — "I forget his name" or "ß òîëüêî ÷òî óçíàë, ÷òî ..." — "I have just learned that ...". The difference is due to the difference in the system of verbal forms reflecting temporal relations: the Russian Perfective Aspect is opposed to the Imperfective as indicating a completed action, while the English Perfect Order is Opposed to the Indefinite as indicating a prior action. The result is evident — the Russian Perfect cannot be connected with the meaning of the Present Tense, while the English Perfect Order can. The outcome of it is that some states represented as actions in Russian have to be in the Past (since the states are results of completed actions), and in English they can be used in the Present tense if the actions and the resulting states coincide or are important at the moment of speaking.
ÞA GRAMMATICAL MEANING IS DEPENDENT.
Dependence of grammatical meanings means that they always accompany some other meanings. Most evident is the fact in the morphological meaning: the grammatical meaning of Number cannot be found in English without a Noun; the grammatical meaning of the Superlative Degree cannot be used without an Adjective. But the same is true for the syntactical grammatical meanings — the grammatical meaning of interrogation cannot be seen without the referential meaning of the sentence used in the interrogative form. More to it: other, most often lexical meaning can modify the grammatical meaning of the form or forbid its use at all: the form of the Continuos Aspect if the verb "to jump" means {repetition}, but not {limited duration} as the form is expected to mean; the transitive verb "to have" does not permit the Passive form.
ÞA GRAMMATICAL MEANING IS ABSTRACT.
Grammatical meanings are abstract because they do not actually depend upon meaningful features they represent. It follows from the oppositive nature of grammatical meaning — the meaning appears not due to direct reference to the outer phenomena but it is connected with them through opposition, through the meaning of other forms composing the opposition.
ÞA GRAMMATICAL MEANING IS OBLIGATORY.
This feature means that a grammatical meaning determines its importance for the system of Language. This feature demands that if the meaning is grammatical then this meaning or its opposite must be found with all units of the class. We have already met the influence of this feature when discussing the modal verbs. Another example: all nouns a meaning of Number. The majority have singular or plural as the form can be, but those that have only one form have either singular or plural but still a meaning of Number. The other reflection of this feature is that the meaning is used even if it is in any other, non-grammatical way: "four birds, "four" already indicates plurality, and still the noun is used in the plural indicating this meaning once more.