Out of all the punctuation marks used in the English language, the colon is by far the most forward-thinking.
More conservative marks are concerned only with the ideas that came before them, but the colon is all about the future. It introduces. It announces. It declares. And it’s the only mark of punctuation with the same name as a digestive organ!
But the colon is also famously squirrely and difficult to use correctly: many folks are never quite sure where and when it should be placed in a sentence. Should a colon divide these two clauses, or a semicolon? Or a dash? Or a period?
How to Use a Colon Correctly
Correct punctuation is important in your writing: poorly punctuated prose is a major turn-off for publishers and readers alike, and can result in your manuscript being rejected for publication—or, at the very least, your audience not taking your writing terribly seriously.
But don’t fret! This comprehensive guide will teach you 9 ways to correctly use colons: where to place them, when best to use them, and how they operate in a sentence.
And as an added bonus, we’ll show you how it’s done: each rule we introduce will be illustrated with an example sentence or two, so you’ll see the colon in action plenty of times before we’re through.
Before we begin, here’s one writ-in-stone rule to remember. No matter what kind of sentence you’re writing, a colon always must come after an independent clause: a clause that can stand on its own as a sentence.
The pallor of his face betrayed him: white as his soul was black.
Ready? Let’s get punctuating!
Use a colon to introduce either a single item or a list of items in a series. In this case, never capitalize the first word after the colon—unless it’s a proper noun!
During the entire four-hour lecture, one name clung in her memory: Bernie.
She asked Gordon to fetch a few things: a barrel of apples, a cask of ale, and a spine to call his own.
However, if the item or list comes after an expression like “for instance,” “for example,” or “namely,” only use a colon if the series includes one or more grammatically complete clauses.
Yasmin yearned for two things, namely, to live, and to have fun.
For example: Ulysses was in charge of stacking the crates; Hogan was busy with tracking down lobsters; and Briggs found himself saddled with babysitting duty.
Use a colon to separate two independent clauses when the second clause explains, illustrates, or elaborates on the meaning of the first.
Here, the colon acts a lot like a semicolon. As before, do not capitalize the first word after the colon unless the noun is proper, or otherwise ordinarily capitalized.
It’s true, I’ve killed my demons: my therapist makes his living sewing together new monsters from the parts.
All three Ellis brothers are involved in the family business: Jethro paints, Willem sews, and Eustace disposes of the bodies.
When two or more closely related sentences follow a colon, capitalize the first word that follows the colon.
When the speaker had everyone’s attention, he made three concise points: First, success was only a stepping-stone on the path to happiness. Second, your happiness should not depend on others. Third, the buffet table at the back of the room had caught fire.
Use a colon to emphasize either a single word or an entire phrase at the end of a sentence.
In a fit of pique and indecision, the traffic light turned a peculiar color: mauve.
Short tempers, pilfered wigs, and broken china: the weekly bridge game was becoming an increasingly tense affair.
Note: In these cases, an em dash (the longest of the dashes) can and often is used for the same purpose as the colon.
There it was, hanging on the bathroom wall—the remarkably lifelike painting of a dog walking a man on a leash.
Use a colon to introduce an extended quotation.
Sir Neibold’s letter to his lady begins: “Fair Lady, I regret to inform you that I have suffered a permanent change of address…”
A word to the wise: Always place colons outside quotation marks and parentheses. And when material ending with a colon is quoted, drop the colon.
Jim found one major flaw in Holst’s true crime short story, “Eggbeater Blues”: the murder weapon was never found.
They’d shoot him at dawn (and probably fricassee him, too): an ignoble end for such a renowned rooster.
When telling time, use a colon to separate the hours from the minutes—with no spaces in between.
The party really got going around 8:30, and wouldn’t start to peter out until dawn.
Use a colon to express a ratio between two numbers.
Mix these two chemicals at a ratio of 4:5.
While in most correspondence, the salutation is followed by a comma, business letters follow it with a stately colon:
Dear Mr. Bushwhacker:
The Homeowners Association has voted against your proposal to include junked cars in our approved list of “Lawn Decorations and Amenities.”
8. Titles and Subtitles
Use a semicolon to separate a book’s title from its subtitle.
R.H. Postmaster is the bestselling author of Six Feet Plunder: A Practical Guide to Grave Robbing.
Use a colon to separate chapters from verses in biblical references, and to separate volumes from page numbers in cited works.
When cornered, Elmo would either quote John 3:16 or recite excerpts from Entertainment Weekly 11:36–38.
Bonus Round: Colons vs. Dashes vs. Ellipses
A big source of confusion surrounding colons is when to use them in place of other punctuation marks, namely, dashes and ellipses. So let’s quickly break down the difference between the three marks:
The truth is, an em dash can sometimes perform the same function as a colon (see item 3 above: “Emphasis”). But while a colon is formal, a dash is quick and casual, almost startled in its mannerisms.
Consider the following:
She sloshed across the patio: eyes dry, galoshes full of mud and silt.
She sloshed across the patio—eyes dry, galoshes full of mud and silt.
Which of these seems more calm and considered, and which seems to move more quickly? Sometimes your punctuation choice is a matter of pacing more than grammar.
The ellipsis, on the other hand, almost never functions like a colon, as it performs an entirely different role.
Use an ellipsis to imply either a pause in the sentence or that something has been omitted for one reason or another.
Howling in frustration, he stabbed downwards again and again: the steak was just too tough to cut.
Howling in frustration, he stabbed downwards again and again…the steak was just too tough to cut.
And that’s all for today! Hopefully by now you know colons inside and out…but if you don’t, feel free to come back and consult this guide whenever you have questions.
Did you enjoy this punctuation lesson? Looking for more ways to polish your prose? Seeker, seek no further: