Adjectivetoadverb

Adjectivetoadverb is a coined term used in linguistics to describe a relation between adjectives and adverbs in which the same word form can function as both an adjective and an adverb without any morphological change. The label highlights a zero-derivation or conversion from the adjective category to the adverb category. The term is not standard in traditional grammar references but is used in descriptive discussions of word formation and cross-linguistic patterns.

In English, a small class of words can act as adverbs without adding -ly. Common examples include fast, hard, late, early, and far, as in “The car goes fast,” “He hit it hard,” “She arrived late,” “We left early,” and “They traveled far.” These adverbs share the same form as their adjective counterparts. Beyond this set, many adjectives do not serve as adverbs in formal writing; adverbs are typically formed with -ly or are irregular (for example, well, fast, hard).

Cross-linguistic variation is relevant to the concept. Some languages reuse the same form for adjective and adverb, while others require a distinct adverbial form or use particles to mark adverbial function. In typological studies, adjectivetoadverbs help describe how different languages handle adverb formation and the boundaries between adjective and adverb categories.

Criticism and usage notes: the term is informal and not widely adopted. For precision, grammars often describe the phenomenon as adverbs formed without derivational morphology or as a case of zero-derivation from adjectives to adverbs. See also: adjective, adverb, zero derivation, word formation.