Turkic adverbs are single-word lexical units serving to modify verbs, verb phrases, adjectives, other adverbs, clauses, and sentences, answering questions such as ‘in what way? and ‘like what?’. They do not constitute morphologically well-defined categories and mostly originate as other parts of speech. Many are petrified case forms, participant nominals, action nominals, and converbs. Some have the same shape as secondary postpositions but differ from them by being unable to govern grammatical cases. The number of nonderived adverbs is highly limited. Turkic adverbs of different subclasses cannot be subsumed under a common semantic prototype.