Functional styles (FS) are the subsystems of language, each subsystem having its own peculiar features in what concern vocabulary means, syntactical constructions, and even phonetics. The appearance and existence of FS is connected with the specific conditions of communication in different spheres of human life. FS differ not only by the possibility or impossibility of using some elements but also due to the frequency of their usage. For example, some terms can appear in the colloquial style but the possibility of its appearance is quite different form the possibility to meet it in an example of scientific style. The classification of FS is a very complicated problem, that is why we will consider ideas of I.V.Arnold and I.R. Galperin, bearing in mind that Galperin treats functional styles as patterns of the written variety of language thus excluding colloquial FS. Both scholars agree that each FS can be recognized by one or more leading features. But Galperin pays more attention to the coordination of language means and stylistic devices whereas Arnold connects the specific features of each FS with its peculiarities in the sphere of communication. According to I.R. Galperin, a functional style of language is a system of interrelated language means which serves a definite aim in communication. A functional style should be regarded as the product of a certain concrete task set by the sender of the message. Functional styles appear mainly in the literary standard of the language. These represent varieties of the abstract invariant and can deviate from the invariant, even breaking away with it.
Each FS is a relatively stable system at the given stage in the development of the literary language, but it changes, and sometimes considerably, from one period to another. Therefore FS is a
