This article presents a comprehensive analysis of the means of expressing diminution and augmentation in the pronominal system of the Yakut language, which serve as key markers of dialectal variation and result from historical-cultural contacts. The study is based on field materials collected by the author fin the northeastern and Vilyui dialect zones Olenyoksky, Kobyaysky, Eveno-Bytantaysky, Ust-Yansky districts, as well as data from the «Dialectologicafl Atlas of the Yakut Language» and other published sources. The methods of linguistic description, comparative analysis, and linguistic geography were applied. Digital technologies, including tools for working with linguistic databases, were used for data processing and systematization. The productive use of diminutive (-čaan, -kaan) and augmentative (-dza, -ndza) affixes with pronouns is established as a stable feature of the northern dialects, contrasting them with the literary norm and central dialects. For the first time, complete paradigms of demonstrative pronoun declension with these affixes are presented, and restrictions on their combinatorial potential are identified (the augmentative implies the possibility of the diminutive, but not vice versa; the –kaan affix has selective compatibility). The results confirm general typological patterns of evaluative morphology and testify to the deep integration of Tungstic substrate elements into the grammatical system of Yakut dialects. The conducted research contributes to the study of dialectal syntax and morphology of the Yakut language, clarifying fts dialectal division and identifying the areas of innovative phenomena. The obtained data are significant for reconstructing language contacts and the history of the Yakut language formation. Future work involves expanding the field materials database, their digital processing, and detailed linguistic cartography.