Compound Adjective Formed With | Rule on Hyphenation | Example |
all | Always hyphenate. | all-inclusive study |
century | Always hyphenate. | twentieth-century technology |
cross | Some hyphenated, some open, some closed. Check the dictionary. | cross-referenced section |
cross-country skis | ||
But: crosscut saw | ||
fold | Closed unless formed with numbers of 100 or more. | tenfold increase |
100-fold increase | ||
full | Hyphenated before noun, open after noun. | full-scale drawings |
The drawings are full scale. | ||
half | Most hyphenated, some closed. Check the dictionary. | half-inch measurement |
half-baked plan | ||
halfway house | ||
halfhearted attempt | ||
high, low, upper, lower, middle, mid | Most hyphenated before noun, open after noun. | high-volume trading |
highbrow organization (check the dictionary!) | ||
middle-class voters | ||
midlife crisis | ||
mid-Atlantic region | ||
Mideast peace process | ||
like | Closed unless root word ends in l or ll or has three syllables or more. | catlike jumping ability |
childlike demeanor | ||
cathedral-like façade | ||
number + odd | Always hyphenate compounds formed with numbers (words or numerals) plus the word odd. | twenty-odd pages |
360-odd days | ||
four-hundred-odd socks . . . | ||
but, four hundred odd socks | ||
number | Always open when used to express a ratio (with the word percent). | ten percent increase |
100 percent change | ||
Number + Unit of Measure | Always hyphenate | three-mile limit |
two-week vacation | ||
150-yard skid mark | ||
Number + Unit of Measure + Adjective | Always hyphenate | two-year-old daughter |
sixty-five-year-old man | ||
two-and-a-half-year-old child | ||
twenty-five-foot-high wall | ||
But: six year-old girls | ||
Number + Number + Unit of Measure + Adjective | Hyphenate the number and then the adjective | twenty-four six-inch-long measurements |
Number + Unit of Measure + Adjective (coming after noun) | Hyphenate the number | a man sixty-five years old (note plural years) |
No hyphen | a wall three meters high | |
Hyphenate the number | twenty-four boys five years old | |
fractional numbers | Hyphenate spelled-out fractions used as adjectives. | two-thirds majority |
In mixed fractions, the whole number is not joined to the fraction by another hyphen. | twenty-one and one-quarter miles | |
four and one-eighth inches | ||
numbers | Hyphenate only the numbers from twenty-one through ninety-nine. All others are open. | twenty-four bottles of beer on the wall |
two hundred rock stars | ||
over, under | Closed unless the word the appears in the compound. | overexposed film |
underrated basketball team | ||
over-the-counter stock market | ||
under-the-table deal | ||
self | Most hyphenated. Closed if prefix un- is added or suffix added to self. | self-confident applicant |
self-conscious speaker | ||
unselfconscious speaker | ||
selfish act | ||
selfless character trait | ||
wide | Always closed unless cumbersome. Cumbersome compounds are hyphenated when they appear before the noun modified and open after the noun modified. | statewide referendum |
worldwide legal services | ||
university-wide crusade (comes before the noun modified) | ||
The crusade was university wide (after noun modified) |
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