This in-depth study delves into the intricacies of Assamese lexical word categories through a comprehensive analysis of derivational morphology. Assamese, a language rich in linguistic diversity, exhibits a complex system of word formation and word categories. By scrutinizing the derivational processes that shape the language, this research unveils the intricate relationships between roots, affixes, and lexical categories. It explores how derivational morphology contributes to word formation, word class membership, and semantic nuances in Assamese. The findings offer a deeper understanding of the language's structural intricacies and contribute to the broader field of linguistics.