Grammar in the systemic conception of language

The grammatical category is a system of expressing a generalized grammatical meaning by means of paradigmatic correlation of grammatical form.
The ordered set of grammatical forms expressing a categorical function constitutes a paradigm.
The paradigmatic correlation of grammatical forms in a category is exposed by “grammatical opposition”. Grammatical opposition is a generalized correlation of lingual forms by means of which a certain function is expressed. The correlated elements (members) of the opposition must possess two types of features: common features and differential features. Common features serve as the basis of contrast, while differential features immediately express the function in question.
The most important type of opposition is the binary privative opposition. The binary privative opposition is formed by a contrastive pair of members in which one member is characterized by the presence of a certain differential feature (mark), while the other member is characterized be the absence of this feature. The member in which the feature is present is called “mark”, “strong” or “positive” and is designated by the symbol + (plus). The member in which the feature is absent is called the “unmarked”, “weak” or “negative” member, and is designated by the symbol – (minus). (past –present: We worked (strong member) – We work (weak member).


GRAMMATICAL CLASSES OF WORDS
The words of language are divided into grammatically relevant sets of classes. The traditional grammatical classes of words are called “parts of speech”. Modern principles of part of speech identification have been formulated as a result of painstaking research. The three conducted names are especially notable for the elaboration of these criteria: V.V.Vinogradov in connection with his study of Russian grammar, A.I.Smirnitsky and B.A.Ilyish in connection with their study of English grammar.
In modern linguistics, parts of speech are discriminated on the basis of the three criteria: “semantic”, “formal”, and “functional”. These factors of categorical characterization of words are referred to meaning, form and function.
The semantic criterion presupposes the evaluation of the generalized meaning, which is characteristic of all the subsets of words constituting a given part of speech. This meaning is understood as the “categorial meaning of the part of speech”.
The formal criterion provides for the exposition of the specific inflexional and derivational (word-building) features of all the lexemic subsets of a part of speech.
The functional criterion concerns the syntactic role of words in the sentence typical of a part of speech.
Words on the upper level of classification are divided into notional and functional, which reflects their division in the earlier grammatical tradition into changeable and unchangeable.