The problem of parts of speech. Words are generally considered to be the basic elements of language. They clearly show up in writing, and they are the items defined in dictionaries. According to various formal and semantic features, all words are divided into three major families of words: lexical (i.e. content) words, function words, insert words. Parts of speech are grammatically relevant classes of words. Since the word is distinguished not only by grammatical, but also by semantic and lexemic properties, some scholars refer to parts of speech as lexico-grammatical series of words (Blokh 1983).