Plane of Content and Plane of Expression
This dichotomy was first studied by Louis Hjelmslev (1899-1965) – Danish linguist, the founder of the of linguistics. Together with he developed a theory of which he called . The main interest of glosssematics was describing the formal characteristics of the language. L. Hjelmslev’s is a development of F. de Saussure's sign model. 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: https://en.wikipedia.org/ 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 of lingual units is phonemic: it is formed by phonemes. The phoneme has no meaning, its function is purely differential. The 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 level is lexemic. Its differential unit is the word. The word realizes the function of nomination. The level is denotemic, its constituent unit is denoteme (notional part of the sentence). The level is proposemic. It is built up by sentences. As a sign, the sentence simultaneously fulfils two functions – nominative and predicative. The