Abstract
The system of the Russian modern language is variable and therefore represented by diverse forms, viewed from the angle of material differences. The article attempts to show isolated sentence members and isolated partial constructions as variant syntactic constructions, just as variant constructions are partial constructions and non-partial constructions. The use of the method of analogy, transformational transformations and the technique of deparcellation was clearly insufficient to consider these syntactic constructions as variable. The purpose of the article is a theoretical justification regarding the recognition of isolated sentence members and isolated partial constructions as variant syntactic constructions, as well as the identification of similarities and differences between them. Isolated parcel constructions are considered against the background of isolated members of the proposal. An analysis of the views of scientists on this issue has shown that isolated members of a sentence and isolated partial constructions have the same characteristic set of isolation, such as: the reason for isolation; semi-predicative relations; syntactic function in a sentence; syntactic relationship between the word being defined and the definition; location. The similarity of the isolated members of the sentence and the isolated parcel constructions is explained by their single mechanism of isolation. However, there is one significant difference between them – in semantics. Separate parcel constructions, unlike separate members of a sentence, differ in the nature of independence, greater semantic, emotional and expressive load, and special expressivity. Our previous research also confirmed that isolated parcel constructions have a maximum degree of intensity of expressivity compared to isolated members of the sentence. Isolated sentence members and isolated partial constructions are variant syntactic constructions, where the latter are endowed with great semantic weight, vivid expression, expressiveness, according to the expectations of expressive syntax.