Usage of hyphens

- Compound adjectives are a combination of two or more adjectives that modify the same noun. They require a hyphen to avoid confusion. Examples include:

French-speaking Small-town Slow-moving Up-to-date
All-too-common Low-risk Ill-equipped Sure-footed
Long-winded Part-time Open-minded Four-year
Erin received high marks on her well-written essay.
Luna installed state-of-the-art technology in her office.

- Phrases with compound adjectives require a hyphen to avoid confusion and ambiguity. Note that once the words are combined, they form an adjective to modify the noun.

Note that numbers written out should include a hyphen between each individual number.


- A prefix is an affix placed at the beginning of another word to modify the word’s meaning. But, when does a prefix need a hyphen? Here are some general rules to follow about hyphenating prefixes.

Common prefixes
(sometimes used with the hyphen, sometimes without)
Pre- Post- Anti- Pro-
Con- Ex- Non- Omni-
Inter- Intra- Macro- Micro-
Auto- Extra- Homo- Hetero-

- Always use a hyphen with a proper noun and the prefixes ex- and self-. Always use a hyphen is there are two of the same vowels in a row. However, different vowels in a row do not require a hyphen. When in doubt, add a hyphen to eliminate confusion.

Re-press (without a hyphen, this could be confused with repress)