A hyphen is a punctuation mark used to join words and to separate syllables of a single word. The use of hyphens is controversial in the English language. Some writers, publishers, and style guides recommend that hyphens should be used rarely, if at all. However, their use can enhance readability when they are applied carefully and appropriately.
There are two main types of hyphens: those used to link two or more words into one term (called “solid” or “end” hyphens) and those used to indicate broken pronunciation (called “suspension” hyphens).
To indicate an optional element:  For example, the phrase “quick brown fox jumps over the lazy dog” does not include a hyphen between “brown” and “fox”. A solid hyphen is sometimes used between two or more related adjectives (for example, “the quick-brown-fox rule”), but this usage is uncommon and considered incorrect by some authorities. To separate digits in numbers less than 10 (for example, 8-2-9), although this usage was common in older typesetting but has been largely replaced.
Last modified: August 17, 2022