Modern linguistics is essentially based on the systemic conception of language. System in general is defined as a structured set of elements related to one another by a common function.

The interpretation of language as a system develops a number of notions, namely: the notions of language levels and language units, paradigmatic and syntagmatic relations, the notions of form and meaning (function), of synchrony and diachrony, of analysis and synthesis, and some others.

The discrimination of language and speech is the fundamental principle of linguistics. This principle has sustained throughout the whole history of the study of language. With a special demonstrative force it was confirmed by I.A. Beaudoin de Courtenay (end of the XIX c.) and F. de Saussure (beginning of the XX c.) who analyzed the language-speech dichotomy in connection with the problem of identifying the subject of linguistics. The two great scholars emphatically pointed out the difference between synchrony and diachrony stressing the fact that at any stage of its historical evolution language is a synchronic system of meaningful elements, i.e. a system of special signs (Blokh, 2000).

Language vs Speech (verbal behaviour)

Saussure made what became a famous distinction between langue (language) and parole (speech, or verbal behaviour). Language, for Saussure, is the symbolic system through which we communicate. Speech refers to actual utterances. Since we can communicate an infinite number of utterances, it is the system behind them that is important, this is the primary object of study for the linguist. According to F. de Saussure, there is langue versus parole. Bylangue, best translated in its technical Saussurean sense as language system, is meant the totality of regularities and patterns of formation that underlie the utterances of a language; by parole, which can be translated as language behaviour, is meant the actual utterances themselves (URL: ht-tps://www.britannica.com/science/linguistics/The-20th-century).

The impact of Saussure's ideas on the development of linguistic theory in the first half of the twentieth century cannot be understated. Two currents of thought emerged independently of each other, one in Europe, and the other in America. The results of each incorporated the basic notions of Saussurian thought in forming the central tenets of structural linguistics.

The most important of the various schools of structural linguistics to be found in Europe in the first half of the 20th century included the Prague school, most notably represented by Nikolay Sergeyevich Trubetskoy and Roman Jakobson, both Russian 'emigr'es, and the Copenhagen (or glossematic) school, centred around Louis Hjelmslev (URL:.

Syntagmatic vs paradigmatic relations

Lingual units stand to one another in two fundamental types of relations: syntagmatic and paradigmatic. Syntagmatic relations are immediate linear relations between units in a segmental sequence (string). One of the basic notions in the syntagmatic analysis is the notion of syntactic syntagma. A "syntactic syntagma" is the combination of two words or word-groups one of which is modified by the other. To syntagmatic relations are opposed paradigmatic relations. They exist between elements of the system outside the strings in which they cooccur. The function of a grammatical paradigm is to express a categorial meaning (Blokh, 2000).

Plane of Content and Plane of Expression

This dichotomy was first studied by Louis Hjelmslev (1899-1965) – Danish linguist, the founder of the Copenhagen School of linguistics. Together with Hans Uldall he developed a structural theory of language which he called glossematics. The main interest of glosssematics was describing the formal characteristics of the language. L. Hjelmslev’s sign model is a development of F. de Saussure's sign model. Saussure considered a sign as having two sides, signifier and signified. Hjelmslev's famously renamed signifier and signified as respectively expression plane and content plane, and also distinguished between form and substance (URL:wiki/Louis_Hjelmslev).

The plane of content comprises the semantic (meaningful) elements of the language; the plane of expression comprises the material (formal) units of the language. Each language sign has a form and a meaning. The two planes are inseparably connected. Grammatical elements of language present a unity of content and expression, a unity of form and meaning.

Levels of Language Units

Units of language are divided into segmental and suprasegmental. Segmental units consist of phonemes, they form phonemic strings of various status. Suprasegmental units do not exist by themselves, but are realized with segmental units and express different modificational meanings reflected on the strings of segmental units (Blokh, 2000).

The segmental units of language form a hierarchy of levels. Units of each higher level are formed of units of the immediately lower level.

Professor M.Ya.Blokh: the lowest level of lingual units is phonemic: it is formed by phonemes. The phoneme has no meaning, its function is purely differential. The second level, located above the phonemic level, is morphemic. The morpheme is the elementary meaningful part of the word built up by phonemes. The morpheme expresses abstract, "significative", meaning. The third level is lexemic. Its differential unit is the word. The word realizes the function of nomination. The fourth level is denotemic, its constituent unit is denoteme (notional part of the sentence). The fifth level is proposemic. It is built up by sentences. As a sign, the sentence simultaneously fulfils two functions – nominative and predicative. The sixth level is the level of topicalization, its constituent element is the "dicteme" ("utterance"). The function of the dicteme is to build up a topical stretch of some text. Being an elementary topical unit of text, the dicteme fulfils four main signemic functions: the functions of nomination, predication, topicalization, and stylization (Blokh, 2000).

The main units of language are considered to be the word and the sentence. Words are studied by morphology, sentences are studied by syntax.

Morphemic Structure of the Word

The word is the nominative unit of language built up by morphemes and indivisible into smaller segments as regards its nominative function (Blokh, 2000). The morphological system of language reveals its properties through the morphemic structure of words. So, it is but natural that one of the essential tasks of morphology is to study the morphemic structure of the word.