Abstract
<jats:p>The aim of the research paper is to identify the structural, semantic and pragmatic features of the complex sentences in English business letters, namely in the genre of commercial correspondence. This is due to the increased role of business communication and the need to quickly and accurately compose persuasive business letters. The quantitative analysis, a descriptive method, comparative methods as well as complex discourse analysis are used in the research. The results of the research have shown how the communicative-pragmatic functions of sentences, the reporting function and the influence function, are realized in business correspondence. The value of the research study would benefit in developing business document writing skills in the rapidly evolving world of business communication. Its importance is also determined by the increased need to study American business communication, since representatives of the American business community are the most numerous strategic partners and investors in the economy of the Republic of Kazakhstan The research results would also be implemented in teaching persuasive writing, practical grammar and enhancing business communicative skills of EFL learners. The paper concludes that complex sentences used in the integration of lexical and syntactic emotionally expressive devices in business texts perform not only an informative function but also an influential one. Each of these functions relies on distinct linguistic resources designed to achieve specific communicative objectives.</jats:p>