Search Our Blog

    Subscribe by Email

    Call for Blog Articles

    Want to share your experiences, advice, or ideas with the GrammarPhile community? Do you have grammar, punctuation, editing questions you'd like answered? Submit guest post ideas or questions to Blog

    Compound Adjectives

    Posted by Julie DeSilva on Nov 29, 2011 5:30:00 AM

    C + ANo aspect of style causes greater difficulty than compound adjectives. When a compound adjective is shown hyphenated in the dictionary, you can assume only that the expression is hyphenated when it occurs directly before a noun. When the same combination of words falls elsewhere in the sentence, the use or omission of hyphens depends on how the words are used.

    Adjective + Noun

    Hyphenate an adjective and a noun when these elements serve as a compound modifier before a noun. Do not hyphenate these elements when they play a normal role elsewhere in the sentence (for example, as the object of a preposition or of a verb). However, if the expression continues to function as a compound adjective, retain the hyphen.

    • high-speed printers; these printers run at high speed
    • a plain-paper fax; the fax uses plain paper
    • red-carpet treatment; roll out the red carpet
    • a part-time job; the job is part-time (compound adjective)
    • a long-term investment in bonds; the investment runs for a long term; but: the investment is long-term (compound adjective)
    • a larger-size shirt; the shirt is a larger size
    • the finest-quality goods; the goods are of the finest quality

    Compound with Number or Letter

    When a number and a noun form a one-thought modifier before a noun (as in six-story building), make the noun singular and hyphenate the expression. When the expression has a normal form and a normal function elsewhere in the sentence, do not hyphenate it.

    • a one-way street; a street that runs only one way
    • a first-person account; a story written in the first person
    • a first-rate job; a job that deserves the first (or highest) rating; but: a job that is first-rate
    • a two-piece suit; a suit consisting of two pieces
    • a 20-year mortgage; a mortgage running for 20 years
    • a 55-mile-an-hour speed limit; a speed limit of 55 miles an hour
    • 24-hour-a-day service; service 24 hours a day
    • an 8-foot ceiling; a ceiling 8 feet above the floor

      Exceptions: a 15 percent decline; a $4 million profit; a twofold increase, but: a 12-fold increase; a secondhand car, but: a second-degree burn
    A hyphenated compound adjective and an unhyphenated possessive expression often provide alternative ways of expressing the same thought. Do not use both styles together.

    • a one-year extension, or a one year's extension, but not: a one-year's extension
    • a two-week vacation, or a two weeks' vacation, but not: a two-week's vacation
    More examples:
    • he does A-plus (or A+) work; a grade of A plus (or A+)
    • in A1 condition; but A.1. steak sauce

    Tags: hyphenation, adjectives