The category of number in Russian adverbs

There is a small and vague group of adverbs in Russian dialects that possess a grammatical category of number. In this article we cover those adverbs that trace back to the forms of the instrumental case. The vast majority of plural forms of adverbs are marked. The vast majority of singular forms of adverbs are unmarked. The number of adverb is a non-syntactic category, which disappears gracefully. Adapted from the source document