Hyphen Use // Purdue Writing Lab

Two words brought together as a compound may be written separately, written as one word, or connected by hyphens. For example, three modern dictionaries all have the same listings for the following compounds:

hair stylist hairsplitter hair-raiser

Another modern dictionary, however, lists hairstylist, not hair stylist. Compounding is obviously in a state of flux, and authorities do not always agree in all cases, but the uses of the hyphen offered here are generally agreed upon.

1. Use a hyphen to join two or more words serving as a single adjective before a noun: a one-way street chocolate-covered peanuts well-known author However, when compound modifiers come after a noun, they are not hyphenated: The peanuts were chocolate covered. The author was well known.
2. Use a hyphen with compound numbers: forty-six sixty-three Our much-loved teacher was sixty-three years old.
3. Use a hyphen to avoid confusion or an awkward combination of letters: re-sign a petition (vs. resign from a job) semi-independent (but semiconscious) shell-like (but childlike)
4. Use a hyphen with the prefixes ex- (meaning former), self-, all-; with the suffix -elect; between a prefix and a capitalized word; and with figures or letters: ex-husband self-assured mid-September all-inclusive mayor-elect anti-American T-shirt pre-Civil War mid-1980s
5. Use a hyphen to divide words at the end of a line if necessary, and make the break only between syllables: pref-er-ence sell-ing in-di-vid-u-al-ist
6. For line breaks, divide already-hyphenated words only at the hyphen: mass-produced self-conscious
7. For line breaks in words ending in -ing, if a single final consonant in the root word is doubled before the suffix, hyphenate between the consonants; otherwise, hyphenate at the suffix itself: plan-ning run-ning driv-ing call-ing
8. Never put the first or last letter of a word at the end or beginning of a line, and don't put two-letter suffixes at the beginning of a new line: lovely (Do not separate in a way which leaves ly beginning a new line.) eval-u-ate (Separate only on either side of the u; do not leave the initial e- at the end of a line.)