Comparison is a feature in the morphology or syntax of some languages, whereby adjectives and adverbs are inflected or modified to indicate the relative degree of the property defined by the adjective or adverb.

The grammatical category associated with comparison of adjectives and adverbs is degree of comparison. The usual degrees of comparison are the positive, which simply denotes a property (as with the English words big and fully); the comparative, which indicates greater degree (as bigger and more fully); and the superlative, which indicates greatest degree (as biggest and most fully). Some languages have forms indicating a very large degree of a particular quality (called elative in Semitic linguistics). Other languages (e.g. English) can express lesser degree, e.g. beautiful, less beautiful, least beautiful.