This document provides a detailed definition and overview of adverbs. It begins by defining adverbs as words that modify verbs, adjectives, other adverbs, determiners, noun phrases, clauses, or sentences. It explains that adverbs typically express manner, place, time, frequency, degree, or certainty. The document then discusses different types of adverbs and their functions, including adverbs of manner, place, time, frequency, and purpose. It also covers the formation of comparative and superlative adverbs and special cases like too and enough.