Compound adjectives formed with an ‑ly adverb, and a participle or another adjective are never hyphenated.
- An overly long speech.
(adverb/overly – adjectives/long) - She is an extremely brave young girl.
(adverb/extremely – adjectives/brave, young) - A highly regarded woman.
(adverb/highly – participle/regarded) - It was a beautifully painted landscape.
(adverb/beautifully – participle/painted)
The same applies to the adverb very.
- A very tired child.
(adverb/very + adjective/tired)
This rule applies only to adverbs. The following two examples are correct because the -ly words are not adverbs:
- A friendly-looking dog.
- A family-run business.
Compound adjectives formed with adverbs not ending in ‑ly are hyphenated when they are before the noun.
- He is a well-known singer in his country.
(adjective/well-known – noun/singer) - The fast-changing situation.
(adjective/fast-changing – noun/situation)
If the compound adjective is after the noun, it is not hyphenated.
- A singer that is well known in his country.
(noun/singer – adjectives/well known) - The situation is fast changing.
(noun/situation – adjectives/fast changing)
