Two words making up a compound may be written like separate words, as one word or they can be hyphenated. Often you may come across the same compound written differently. (e.g. hairstylist or hair stylist). Linguists still argue on particular uses of hyphen and cannot come to a common opinion, but we have not included controversial issues in the list below. The rules presented below are generally approved and agreed upon.
You should use a hyphen:
- to join two or more words serving as a single adjective before a noun: e.g. a well-organized reception.
However, if a compound adjective follows the noun, no hyphen is necessary: The reception was well organized.
- with compound numerals: seventy-one.
- with spelled out fractions: Their party won the elections by a two-thirds majority.
- to avoid ambiguity: Re –cover (re-cover the baby with a blanket ) vs recover ( to recover from a disease)
- with the prefixes ex-, self-, all-: ex-president, self-confident, all-important
- with the suffix –elect: president -elect
- between a prefix and a capitalized word: pro-American
- with figures or letters: mid -1960s
- to break words at the end of a line if needed, and make the split only between syllables: gre-at, won-der-ful.