Do Function Words Belong to Part of Speech?

The term "function words" ("auxiliary part of speech") in traditional grammars of Kazakh and Russian languages have different connotations due to its functions. In foreign linguistics function words generally are not regarded in opposition to the traditional grammatical classes of words, although sometimes stand for relatively close category of words, which include articles, prepositions (postpositions) and conjunctions. In the 60-70 years of the twentieth century the function words in Kazakh language have sufficiently been investigated, but within the development of linguistics in the Kazakh according to some scholars the function words as a complex phenomenon suggested to regard them as a separate set of words. The theoretical significance of this article is the authors attempt to reveal the linguistic characteristics of function words in Kazakh language, to show their place in language, as well as to determine their nature as a part of speech.