130. Hyphenation Rules

Authorities disagree on hyphenation more than on any other punctuation mark. Also, there are just too many rules for one human being to learn. Therefore, the following rules should be considered as guidelines only.

Hyphens Between Words

Rule 1. To check if a compound noun is two words, one word, or hyphenated, you must look it up in the dictionary. If you can't find the word in the dictionary, treat the noun as separate words.

Examples eyewitness, eye shadow, eye-opener
NOTE: All these words had to be looked up in the dictionary to know what to do with them!

Rule 2. Phrases that have verb and noun forms should appear as separate words when used as verbs and as one word when used as nouns.

Examples The engine will eventually break down. (verb)
We suffered a breakdown in communications. (noun)

Rule 3. Compound verbs are usually hyphenated or appear as one word. If you do not find the verb in the dictionary, hyphenate it.

Examples To air-condition the house will be costly.
We were notified that management will downsize the organization next year.

Rule 4. Generally, hyphenate between two or more adjectives when they come before a noun and act as a single idea.

Examples his easy-going nature BUT By nature, he is easy going. one-way street BUT This street is one way.
bright young woman (No hyphen appears because bright and young are two separate ideas.)

Rule 5. Remember to use a comma between two adjectives when you could have used and between them.

Example I have classified, secret information.

Rule 6. An adverb that does not end in ly followed by an adjective in front of a noun should be hyphenated.

Example well-known actress BUT The actress is well known.

Hyphens with ly Words

Rule 1. When the first word of the two-word modifier ends in ly, hyphenate if the ly word acts as one idea with the second word AND the ly word can be used alone with the noun (i.e., the ly word is an adjective).

Example friendly-looking man
Friendly modifies looking and is an adjective describing man.

friendly little girl
No hyphen is used because friendly does not act as one idea with little.

brightly lit room
Brightly is an adverb because it could not be used to describe room.

Rule 2. When the word and can be inserted between the ly word and the next adjective, use a comma between them.

Example A lovely, fragrant bouquet was sent to Jennifer on Valentine’s Day.

Hyphens with Prefixes

Rule 1. The current trend is to do away with unnecessary hyphens. Therefore, attach prefixes and suffixes onto root words.

Example noncompliance, copayment, semiconscious, fortyish

Exceptions bell-like (Avoid three l’s in a row.)
non-civil service position (Use the hyphen with compound words or words already hyphenated.)

Rule 2. Hyphenate prefixes when they come before proper nouns.

Example un-American

Rule 3. Hyphenate prefixes ending in a or i only when the root word begins with an a or i.

Examples ultra-ambitious
semi-invalid

Rule 4. Double e’s and double o’s are usually made into one word.

Examples preemployment, coordinate

Exceptions de-emphasize, co-owner

Rule 5. When a prefix ends in one vowel and a root word begins with a different vowel, generally attach them without a hyphen.

Examples antiaircraft, proactive

Rule 6. Hyphenate all words beginning with self except for selfish and selfless.

Examples self-assured, self-respect, self-addressed

Rule 7. Use a hyphen with the prefix ex.

Example His ex-wife sued for nonsupport.

Hyphens with re Words

Rule 1. Use the hyphen with the prefix re only when:

a. the re means again, AND

b. omitting the hyphen would cause confusion with another word.

Examples Will she recover from her illness? (Re does not mean again.)

I have re-covered the sofa twice. (Re does mean again AND omitting the hyphen would have caused confusion with another word.)

The stamps have been reissued. (Re means again but would not cause confusion with another word.)

I must re-press the shirt. (Re means again AND omitting the hyphen would have caused confusion with another word.)