Compound Adjectives

A compound adjective fuses two or more words into a single modifier through hyphenation. The hyphen signals to the reader that the words belong together as one idea before the noun: a last-minute suggestion, an up-to-date computer, a well-written essay. Without the hyphen, the meaning can shift or collapse entirely—a small business owner could be a business owner who is small in stature, while a small-business owner is unequivocally someone who owns a small business.

Compound adjectives can be built from nearly any part-of-speech pairing. Common combinations include adjective plus adjective (blue-green), adjective plus noun (part-time), noun plus adjective (ice-cold), quantifier plus noun (ten-storey building), noun plus participle (record-breaking), adjective plus participle (old-fashioned), and adverb plus participle (well-oiled). Prepositions can also anchor the compound: up-to-date, out-of-the-way, face-to-face. The hyphen links words that would otherwise read as separate syntactic units, creating a single prepositive modifier that follows the rules of Attributive Adjectives.

When compound adjectives appear after a linking verb in predicative position, the hyphen is often dropped. You write a well-known author but the author is well known. This is not a hard rule, but it is a widely observed convention in edited prose. Proper nouns, however, are never hyphenated in compounds: a New York restaurant, not a New-York restaurant. And be careful not to confuse a compound adjective with an adverb-adjective pair: a very brave soldier contains the adverb very modifying brave—there is no hyphen because very does not join with brave to form a new lexical unit. Only when the combination acts as a fused modifier before a noun does the hyphen become necessary.