Hyphenation Rules

Hyphenation Station
Rule 1

Phrases that have verb, noun, and adjective forms should appear as separate words when used as verbs and as one word when used as nouns or adjectives.

Examples:

The engine will eventually break down. (verb)

We suffered a breakdown in communications. (noun)

Please clean up your room. (verb)

That Superfund site will require specialized cleanup procedures. (adjective)

Rule 2

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

Examples:

friendly-looking man  (compound adjective in front of a noun)

friendly little girl  (friendly and little are separate ideas, but not a compound adjective)

brightly lit room (Brightly is an adverb describing lit, not an adjective.)

Rule 3

When adverbs not ending in -ly are used as compound words in front of a noun, hyphenate. When the combination of words is used after the noun, do not hyphenate.

Examples:

The well-known actress accepted her award.

(Well is an adverb followed by another descriptive word. They combine to form one idea in front of the noun.)
The actress who accepted her award was well known. (Well known follows the noun it describes, so no hyphen is used.)

Rule 4

Remember to use a comma, not a hyphen, between two adjectives when you could have used and between them.

Examples:

I have important, classified documents.

Jennifer received a lovely, fragrant bouquet on Valentine's Day.

Rule 5

Hyphenate all compound numbers from twenty-one through ninety-nine.

Examples:

The teacher had thirty-two children in her classroom.

Only twenty-one of the children were bilingual.

Rule 6

Hyphenate all spelled-out fractions.
Examples:

You need one-third of a cup of sugar for that recipe.

More than one-half of the student body voted for removing soda machines from campus.

Rule 7

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

Examples:

self-assured

self-respect

self-addressed

Rule 8

Use a hyphen with the prefix ex.

Example:

His ex-wife sued for nonsupport.

Rule 9

Use the hyphen with the prefix re only when:

the re means again AND 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.)

I must re-press the shirt.

(Re means again AND omitting the hyphen would have caused confusion with another word.)