48a Use hyphens with compound words.
Some compounds are one word (rowboat, pickup), some are separate words (hard drive), and some require hyphens (sister-in-law). You should consult a dictionary to be sure. However, the following conventions can help you decide when to use hyphens with compound words.
Compound adjectives
Hyphenate most compound adjectives that precede a noun but not those that follow a noun.
| a well-liked boss | My boss is well liked. |
| a six-foot plank | The plank is six feet long. |
In general, the reason for hyphenating compound adjectives is to facilitate reading.
Without the hyphen, living may seem to modify room dividers.
Never hyphenate an -ly adverb and an adjective.
Fractions and compound numbers
Use a hyphen to write out fractions and to spell out compound numbers from twenty-one to ninety-nine.
| one-seventh | thirty-seven |
| two and seven-sixteenths | three hundred fifty-four thousand |