I used to feel pretty confident in my grasp of grammar and style rules, until my first encounter with the Associated Press Stylebook (AP style) and its distinct guidelines. AP style is widely used in journalism and other professional writing, but it can still seem unfamiliar and confusing to uninitiated writers.

To make this popular style easier to understand and use, we’ve delved into tricky issues like AP style numbers in previous blogs. Today, we’ll look at another frequently misunderstood topic: when to use a colon in AP style.

When To Use a Colon in Lists

One of the most common uses for a colon is introducing a list or series of items at the end of a sentence. One common question that is asked in regards to when to use colons in lists is “Is the first word after a colon capitalized?”. In AP style, the word that begins the list or series should generally only be capitalized if it is a proper noun.

When To Use a Colon With Capitalization:

• The puppy left a trail of destroyed items in his wake: shredded papers, mangled stuffed animals and what looked like the remains of a shoe.

However, if the list or series extends over multiple sentences, you should capitalize the first word after the colon in AP Style.

When To Use a Colon Without Capitalization:

• The puppy’s owners had tried everything to address this troubling habit: They paid for professional training. They worked on keeping their house cleaner. They tried to convince themselves that this was a perfect way to get rid of clutter.

How To Use a Colon To Introduce Another Sentence

A colon can also introduce a complete sentence that clarifies or expands on the original sentence. In this case, AP style diverges from some style guides by requiring you to capitalize the first word after the colon.

•  We learned a sad lesson that day: Cooking projects and artwork inspired by Pinterest never come out looking remotely like the posted photos.

When to Use a Colon for Emphasis

Let’s talk about another common use for colons: giving emphasis. As the colon example above shows, a colon can help call attention to the word or phrase that follows it. When using a colon this way, don’t capitalize the first word after it unless the word is a proper noun.

• He believed that no good dessert recipe was complete without one thing: peanut butter.
• She believed that no good dessert recipe was complete without one thing: Nutella.

When To Use a Colon To Offset Dialogue, Q&A or Quotations

In AP style, colons are also used in dialogue and interviews that are printed in question-and-answer style. Here, the colons serve to separate the speakers from the quoted material.

How To Use a Colon To Separate Speakers:

• Travel buddy: I’ve been packing for this trip all week! What about you?
• Me (guiltily): Um, I basically did it all in the last 20 minutes …

Colons can also introduce quotations, and like most punctuation marks, they can be tricky to use correctly in this context. AP style makes these colon rules a little more interesting by inserting some comma guidelines in regards to quotations. If a quotation consists of a single sentence, you should introduce it with a comma and quotation marks. If the quotation is longer than one sentence or forms its own paragraph, replace the comma with a colon.

How To Use a Colon To Introduce Quotations:

• Thomas Jefferson once observed, “The most valuable of all talents is that of never using two words when one will do.”
• George R.R. Martin reportedly said: “Some writers enjoy writing, I am told. Not me. I enjoy having written.”

When To Use a Colon To Separate Numbers

In AP style, colons are also used to separate the elements in several listings. You should place a colon between the units of time when indicating an amount of time that has elapsed or a time of day. In legal or biblical citations, you should use a colon to break up chapters, sections or verses.

• The 2:30 p.m. cookie break was a cherished tradition at their office.
• When Christian quarterback Tim Tebow threw 316 passing yards and averaged 31.6 yards per completion in his first pro football game, some fans drew connections to the Bible verse John 3:16.

Additional Tips on How To Use a Colon

In case the above wasn’t already enough to memorize, here are a few other guidelines for using colons in AP style.

• Don’t place colons after sentence fragments; whatever precedes the colon should always be able to stand on its own.
• Additionally, you should never put a dash next to a colon, since the dash simply doesn’t serve any purpose in this construction.

Final Takeaways on When To Use a Colon in AP Style

With these AP style colon rules in mind, knowing how and when to use a colon in AP style should be much easier. If you have any unanswered questions or tips of your own to add, make sure to let us know in the comments section!