hyphens in compound modifiers
When a compound modifier takes a hyphen.
Hyphenate a compound modifier before the noun: a high-risk plan, a well-known rule. The hyphen shows that the words form one modifier. A cold-water swimmer swims in cold water. Without the hyphen, cold water swimmer is read as a water swimmer who is cold.
Compounds that dictionaries list with a hyphen keep the hyphen after the noun: The tenant is self-employed. Compounds formed with well take the hyphen before the noun and stay open after it: the rule is well known.
Do not hyphenate an adverb ending in -ly and the word it modifies: a freshly painted bench. An adverb cannot modify a noun, so no hyphen is needed. Words that end in -ly but are adjectives follow the general rule: an early-morning shift.
When two compounds share a final word, keep the hyphen on the first and follow it with a space: wood- and coal-burning stoves.
An established open compound stays open as a modifier: a civil rights lawyer.
See also hyphen with adverbs ending in -ly; hyphen with ages and measurements; hyphen with prefixes.
Examples
UseThe county posted a one-way detour around the bridge. (The hyphen joins the two words into one modifier.)
UseReconciling the ledger by hand is time-consuming. (The compound is listed with a hyphen, so the hyphen stays after the noun.)
UseThe rumor about the merger turned out to be well founded. (A well compound stays open after the noun.)
AvoidThe airline announced a last minute gate change. (Last minute is the error: the two words modify gate change as one unit. Write The airline announced a last-minute gate change.)
AvoidThe recently-renovated library reopened in May. (Recently-renovated is the error: an adverb ending in -ly takes no hyphen. Write The recently renovated library reopened in May.)