This article explores the comparative typology of subordinating conjunctions among auxiliary parts of speech in the Azerbaijani and Russian languages. The study aims to identify and analyze the structural and functional characteristics of subordinating conjunctions in both languages, highlighting their similarities and differences. Through comprehensive linguistic analysis, the research examines the usage patterns of auxiliary parts of speech, focusing on their roles in constructing complex sentences and expressing subordinate clauses. The article presents distinctive features of subordinating conjunctions in Azerbaijani and Russian, offering insights into their syntactic behaviors and semantic effects. This comparative approach aids in a broader understanding of conjunction usage in Turkic and Slavic languages, emphasizing the importance of auxiliary parts of speech in language structure and communication.