General Rules:

  • Hyphens join two or more words to form one idea or help avoid ambiguity.

  • Use hyphens only when necessary to avoid confusion.


Avoiding Ambiguity


Rule: Use a hyphen when not using the hyphen clouds the intended meaning.

  • Example: The CEO intends to speak with a group of small-business men.
    “Businessmen” is usually one word; however, it does not make sense here. To show that the sentence refers to a group of men who own or run small businesses, the hyphen is used.


Compound Modifiers (Adjectives)

A compound modifier is two or more words that express a single concept.


Rule: When a compound modifier precedes the noun it modifies, use a hyphen with all words in the modifier. Do not hyphenate a compound modifier when one word is “very” or an adverb ending in “ly.”

  • Example: a well-known author
  • Example: a better-suited alternative
  • Example: a greenish-yellow blanket
  • Example: a very good cake
  • Example: a slyly worded poem


Exception: When a compound modifier that is hyphenated when it’s before the noun it modifies appears after the noun and directly after a form of the verb “to be,” use a hyphen to avoid confusion.

  • Example: The author is well-known.
  • Example: The student is quick-witted.
  • Example: The authors are well-known.


Compound Modifiers That Use Duplicated Vowels or Tripled Consonants


Rule: Use a hyphen to avoid duplicated vowels and tripled consonants for compound modifiers.

  • Example: anti-inflammatory
  • Example: bell-like


Suspensive Hyphenation


Rule: Use suspensive hyphenation when two hyphenated phrases share a common element.

  • Example: short- and long-term investments
  • Example: small- and medium-sized businesses
  • Example: 10- to 20-year sentence