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:
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.
- Use a hyphen to join two or more words serving as a single adjective before a noun:
a one-way streetHowever, when compound modifiers come after a noun, they are not hyphenated:
well-known authorThe peanuts were chocolate covered.
The author was well known.
- Use a hyphen with compound numbers:
Our much-loved teacher was sixty-three years old.
- 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)
- 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:
- Use a hyphen to divide words at the end of a line if necessary, and make the break only between syllables:
- For line breaks, divide already-hyphenated words only at the hyphen:
- 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:
- 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 to leave 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.)