In the modern world, with its diversity of languages and nations, the development of a linguistic personality is one of the main factors of language education.A language personality should possess the language competence that presupposes the possession of the theoretical norms of the language and their further use in the practice of speech use.The language personality must possess the phonetic and lexical grammatical norms of the language.Syntax, which gives the language a communicative and functional significance, is the highest level of the language system.It is in the syntax that the national specificity of the language manifests itself.Possession of it indicates the formation of a language personality.Complex thoughts that reflect the intellectual level of the individual are formed in the form of complex sentences.The emotionality and expressiveness of complex sentences are created due to the way they are organized and the use of syntactic figures of speech.Conversational and expressive elements in the structure of a complex sentence, due to their unintentional and informal nature, create additional shades of imagery and expressiveness in book speech.In the Mari language, the following elements of colloquial speech are introduced in the language of fiction to give a complex sentence imagery and expressiveness: conjunctions, particles, postpositions, interjections, onomatopoeic words and various types of repetitions.Complex and compound sentences are characterized by the use of all these elements of colloquial speech.Conjunctionless complex sentences, based on their structure, use the speech elements of repetition as an expressive means.