Introduction. Complex sentences in the Udmurt language are characterized by the polyfunctionality of many conjunctions and connective words. Nowadays for the conjunction shuysa ‘what’ in Udmurt linguistics only its explanatory function is traditionally distinguished. Meanwhile, the specified token can have a set of additional meanings. The purpose of the article is to reveal the functionality of the conjunction shuysa in the modern Ud-murt language. Materials and methods. The research was carried out on the analysis of examples from literary and folklore texts included in the base of the National Corpus of the Udmurt language. The main research methods were the method of continuous sampling, contextual analysis and the descriptive method. Research results, discussion. The article systematizes the scientific works of domestic and foreign researchers devoted to the study of Udmurt conjunctions. The conducted research made it possible to concretize and clarify the func-tions of the conjunction shuysa ‘what’. It is noted that in the system of the modern Udmurt language, the con-junction of shuysa ‘what’ is multifunctional. Conclusion. Based on the analysis of the National Corpus of the Udmurt language, it was revealed that the multifunctional and postpositive conjunction shuysa ‘what’ in the texts of Udmurt fiction is used in subordinate explanatory, determinative, target and causal. The frequency of use of each of these semantic meanings is different. Most of the complex sentences with the conjunction under study arose on the basis of constructions with direct speech, in which shuysa closes the syntactic unity, which is someone else’s speech. Explanatory complex sentences of the Udmurt language can be transformed into a sim-ple sentence with a non-postpositive verbal clause or with a postpositive verbal clause.