Colons may be the least used punctuation mark, but colons call attention to details without taking up a lot of space or requiring a new sentence. Colons specifically tell the reader to STOP and pay attention because what follows the colon directly relates back to the sentence/s that came before.

Use colons.

• To announce a list or quotation.

Example: Our list of camping gear read as follows: deck of cards, marshmallows, French press coffee pot, and two large cans of bug spray.

Example: My roommate has two hobbies: eating and sleeping.

Example: Consider the words of John F. Kennedy: "Ask not what your country can do for you; ask what you can do for your country."

Example: In her book Writing Your Dissertation in Fifteen Minutes a Day , Joan Bolker (1998) claims: "You can write for a very long time on any given day, but.you can't then do it again the next.and writing daily is the pattern that's best suited to finishing a dissertation" (p. 45).

• To set off a phrase that summarizes or explains the previous sentence/s .

Example: Laughter is good medicine: it cures the blues.

Example: Studies show that female vampire bats cluster together during the day but redistribute themselves at night in order to maintain a fluid social organization: vampire bats are remarkably social.

• After the salutation in a formal letter .

Example: Dear Sir or Madam:

• To indicate hours, minutes, seconds .

Example: The plane landed on time at 7:05 P.M., London time.

Example: He finished the relay in 17:46:14, beating his performance the previous year by a full minute.

• Between a title and subtitle .

Example: The title of my first book is going to be Living in the Library: My Life as a Graduate Student.

Example: The workshop, "Grammar and Punctuation: Unlearning Sentence-Level Errors," was widely attended and terrifically exciting thanks to the facilitator dressing up as an exclamation point!

• Between chapters and verses of the Bible .

Example: Song of Songs 4:15

Do not use the colon.

• After certain words or phrases (e.g., including, such as, for example ) .

Error: Communities have begun printing pamphlets such as : "Helping Your Child Enjoy Recreational Sports" and "Tempering Parent Egos during Little League Games." (the sentence would read fine without the colon; alternatively, a comma before "such as" would set off the additional information)

• After a preposition (e.g., as, of, before, for, from, to, in, on, across, after ) .