hyphens: compound adjectives
Follow the guidelines below when deciding whether to hyphenate different types of compound adjectives.
Compounds that require hyphens
The following types of compounds require hyphens some or all of the time.
Hyphenate compounds with the structure noun-plus-adjective (in that order), whether they are used before the noun or after the verb:
- duty-free goods / The goods were duty-free.
- tax-exempt bonds / The bonds are tax-exempt.
Hyphenate noun-plus-participle compounds regardless of the position:
- snow-capped mountains / The mountains are snow-capped.
- a time-consuming activity / This activity is time-consuming.
Exceptions: There are a number of them, including handmade and handwritten.
Hyphenate two-word compound adjectives consisting of a noun plus a gerund when they come before the noun:
- the decision-making process
- a problem-solving approach
- a profit-sharing plan
- a tape-recording session
See also hyphens: nouns with gerunds.
Adjective-plus-noun or participle-plus-noun
Hyphenate adjective-plus-noun and participle-plus-noun compounds modifying another noun:
- full-time employment
- large-scale development
- special-interest groups
- working-class attitudes
- compressed-air engine
When the compound is used predicatively, keep the hyphen only when the expression acts as an adjective:
- The development was large-scale.
- His position is full-time.
- Development proceeded on a large scale.
- He works full time.
Hyphenate adjective-plus-participle compounds, whether they are used before the noun or after it:
- an odd-sounding name / The name was rather odd-sounding.
- a smooth-talking salesman / The visitor was smooth-talking.
Hyphenate compounds made up of an adjective plus a noun to which the ending ed has been added, in any position in the sentence:
Hyphenate compound adjectives made up of a preposition and a noun:
- after-tax income
- in-service courses
- on a per-gram basis
- out-of-province benefits
Compounds ending in adverbs
Hyphenate compound adjectives whose final constituent is an adverb of direction or place (in, out, down, up, etc.) when they precede the noun:
- a built-up area
- a drive-by shooting
- all-out competition
- the trickle-down theory
Compounds containing verbs
Hyphenate a compound adjective that contains a finite verb:
- a pay-as-you-go approach
- a would-be writer
- a work-to-rule campaign
Phrases of three or more words
Hyphenate phrases of more than two words that include an adverb or preposition and that are used as attributive adjectives (i.e. before the noun):
- a long-drawn-out affair
- an up-to-date approach
- the cost-of-living index
- a subject-by-subject analysis
- on-the-job training
Hyphenate compound proper adjectives that form a true compound:
- Anglo-Saxon period
- Sino-Russian border
- Austro-Hungarian Empire
- Greco-Roman art
But do not hyphenate those in which a proper adjective is combined with a simple modifier:
- Latin American governments
- Middle Eastern affairs
- North American interests
- Central Asian republics
Hyphenate compound adjectives made up of two adjectives that describe a colour without the suffix ish, whether they are placed before or after the noun.
- It was covered with blue-green algae.
- It was blue-green.
Hyphenate compounds with the suffix ish only when they precede the noun:
- The tree had bluish-green leaves.
- The leaves were bluish green.
Do not hyphenate adjectives indicating a specific shade (even if they precede the noun):
- dark green paint
- a bright red dress
- strawberry blond hair
Compounds that are NOT hyphenated
- Do not hyphenate French or foreign words used as adjectives or placed in italics:
- a pure laine Quebecker
- a dolce far niente attitude
- a priori reasoning
Note that this rule does not apply to French or foreign words no longer considered as such:
- avant-garde filmmaking
- a laissez-faire approach
- Do not hyphenate proper nouns used as adjectives:
- a Privy Council decision
- a New York State chartered bank
- Do not hyphenate words in quotation marks:
- a “zero tolerance” approach
- Do not hyphenate chemical terms used as adjectives:
- a calcium nitrate deposit
- a sodium chloride solution
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