In this article, the historical development of sentential negation is compared across the Japonic, Koreanic, Tungusic, Mongolic, and Turkic languages to make inferences about the expression of negation in the common Transeurasian proto-language. Integrating typological considerations, including grammaticalization theory, into the argumentation, the approach taken here differs from previous studies, which are limited to form–function comparison of individual markers. The historical development of negation in the Transeurasian languages is argued to involve a grammaticalization pathway whereby an independent negative verb developed into a preposed negative auxiliary and then, either transferred its inflection to the lexical verb to become an invariant preposed particle or, else, moved to a postposed position to become a suffix on the lexical verb. Taken together with the form–function correspondences of the negative markers, these correlations lead to the reconstruction of genealogically motivated cycles of grammaticalization in the Transeurasian family.