Are you a writer interested in learning more about the colon and its uses in writing?
Maybe you just want to learn more about punctuation marks, including the colon.
Whatever your reasons, I can help you.
I wrote this article to discuss the colon and its correct uses in writing.
Table of Contents
What Is a Colon in Writing?
A colon is a punctuation mark with two vertically aligned dots (:).
The colon has different uses:
- Connecting closely related sentences
- Introducing a list or explanation
- Giving emphasis
When using proper grammar in written language, punctuation marks play a critical role because they provide structure and complete sentences.
A punctuation mark can also change the core message of a sentence and affect its feel and tone.
However, too much or inappropriate use of any punctuation mark can make your sentence vague or misleading.
What Does a Colon Do?
People may not use the colon as much as the period or comma, but it’s useful for emphasizing a word or phrase, connecting sentences, and more.
Using punctuation correctly is crucial because it adds clarity and precision to your writing. It also allows you to pause, stop, or highlight specific parts of a sentence.
Here’s how to use a colon to make your writing clearer and more compelling.
The colon can emphasize a word or phrase, creating more impact in your writing.
Ensure you only capitalize the word after the colon if the next sentence is an independent clause (a complete sentence).
The rice fields have been dry for two straight years: The farmers are now thinking of leaving the town for good.
Introduce Additional Information.
One of the most common uses of a colon is to introduce additional information, such as lists, words, and independent clauses.
She prepared all the ingredients: pasta, olive oil, garlic, dried herbs, salt, cheese, and pancetta.
The boy found what was missing: peace.
Introduce a Quote.
When a colon introduces quotation marks, capitalize the first word after the colon, even if it isn’t a proper noun.
Example: Abraham Lincon said: “Whatever you are, be a good one.”
Clarify Lectures, Book Titles, and Other Compositions.
When you want to use a colon to express two parallel ideas, they should be able to stand on their own.
My favorite collection of short stories is “Old Babes in the Wood: Stories by Margaret Atwood.”
Connect Two Related Sentences.
Use the colon to connect two independent clauses that are closely related, like when the second sentence supports the first sentence.
Example: My friends and I can’t wait for the summer: We’re going to Paris!
In the example above, the second sentence is closely related to the first one.
While a period is acceptable, doing so would eliminate the relationship between the two sentences.
Non-Grammatical Use of the Colon
This punctuation mark has other non-grammatical uses.
Here are examples.
Time: It is now 8:35 p.m.
Ratio: Hunger affects 1:4 children.
Bible verses: Luke 18:22 says, “Sell everything you have and give to the poor.”
Colon vs. Semicolon
It is not uncommon for people to erroneously use semicolons (or other punctuation marks) when a colon would have been more appropriate.
The colon and the semicolon serve vastly different purposes. Thus, you shouldn’t use them interchangeably.
Like the colon, you can use the semicolon to connect two related sentences. However, there is a slight difference between the two punctuation marks.
A semicolon connects two sentences less specifically related to each other than those linked by a colon.
The sentence after a semicolon may not explain or describe the previous sentence.
With the colon, the second sentence ALWAYS explains the previous one.
Colon: Anna asked me a tricky question: Who was the most guilty? (The second sentence explains the first one by revealing the question.)
Semicolon: Anna asked me a tricky question; it was something I was never expecting. (While the two sentences are related, the second does not clarify or explain the first.)
Colon vs. Emdash
People use the colon and emdash to introduce the next part of a sentence.
It’s common for people to use the two punctuation marks interchangeably without realizing that they provide different effects.
An emdash is more potent than a colon.
You must think of a colon as a more “relaxed” punctuation informing you that something more is coming.
Take a look at the examples below and see how these two punctuation marks create a different effect.
Colon: She likes two things: reading and sleeping.
Emdash: She likes two things—reading and sleeping.
The emdash creates more “drama” and anticipation because its long horizontal line draws the eyes and prompts the readers to prepare for a critical or dramatic statement.
Something shocking, unexpected, or interesting often follows the emdash.
By contrast, a colon acts like its boring cousin, introducing mundane and predictable things.
However, don’t confuse an emdash (—) with a hyphen (-) since the former is much longer.
The emdash got its name because it’s about the same length as the capital “M.”
Colons and Emdashes in Quotation Marks
It’s common for writers to confuse how to use a colon or emdash when there are quotation marks in the equation.
Fortunately, the rule is not as complex as you think.
Generally, you use colons and emdashes the same way relative to quotation marks: Both are outside the quotation marks.
Here are two examples.
- The cat has found its new “best friend”: the hamster.
- The cast has found its new “best friend”—the hamster.
While you always place colons and emdashes outside the quotation marks, commas are different because they go inside.
- The cat has found its new “best friend,” the hamster.
Colon vs. Comma
Sometimes, you can also use a comma where you’d use a colon or emdash.
However, each one creates a slightly different tone and feel.
Look at the three examples below.
- The cat has found a new best friend: the hamster.
- The cat has found a new best friend—the hamster.
- The cat has found a new best friend, the hamster.
While all the sentences mean the same thing, each has a slightly different tone and feel.
The colon emphasizes “the hamster,” and the emdash creates a more dramatic introduction.
Meanwhile, the comma “feels” more formal and less intrusive than the other two punctuation marks.
The comma can join two components and introduce quotations after a dependent clause.
People typically use the colon to represent a list of existing components and introduce quotations after an independent clause.
Common Mistakes When Using a Colon
Now you know how to use a colon and what makes it different from the semicolon, emdash, comma, and other punctuation marks.
I will discuss when not to use the colon.
It Should Not Interrupt a Complete Sentence.
Never use colons to interrupt a complete sentence.
✖ The grocery list includes: whole milk, butter, onion, garlic, and bread.
✔ The grocery list includes the following items: whole milk, butter, onion, garlic, and bread.
The colon is unnecessary in the first example because the sentence would still make sense even after removing this punctuation mark.
In the second example, removing it will result in confusion.
It Shouldn’t Follow an Incomplete Sentence.
Regardless of what follows a colon, most grammar books recommend that only a complete sentence come before it.
✖ Things needed: scissors, papers, and glue.
✔ The things you need to prepare are the following: scissors, papers, and glue.
It Shouldn’t Come Between a Preposition and Its Object.
This is the most common mistake people commit when using a colon.
✖ Her favorite pizza recipe is made of: mozzarella, tomato sauce, basil, and prosciutto.
✔ Her favorite pizza recipe is made of these ingredients: mozzarella, tomato sauce, basil, and prosciutto.
It Shouldn’t Follow “Including,” “Especially,” and Similar Phrases.
This mistake violates the grammar rule that the colon should always follow a complete sentence.
✖ The boy has several exotic pets, including: iguanas, tarantulas, hedgehogs, and rodents.
✔ The boy has several exotic pets: iguanas, tarantulas, hedgehogs, and rodents.
It Shouldn’t Precede a Capitalized Word Unless It Introduces an Independent Clause.
The first word after a colon should be capitalized when it’s part of a sentence that can stand on its own.
✖ The team was ecstatic: they were chosen to represent the school!
✔ The team was ecstatic: They were chosen to represent the school!
How to Check for Mistakes
If you’re unsure whether using a colon makes sense, ask yourself this question: Does the sentence before the colon stand on its own, or does it provide a complete thought?
If the answer is yes, you are using it correctly. If not, you may be using the colon incorrectly.
✔ You must bring these items: a bottle of sunscreen, a water jug, and hiking shoes.
✖ Some tips: bring a bottle of sunscreen, a water jug, and hiking shoes.
Meanwhile, the rules for capitalizing the first word after a colon depend on different style guides (ex., Chicago, AP, AMA, MLA, Elements of Style, etc.).
The general rule is that the first word following a colon should be lowercase if it’s part of a dependent clause, which can’t stand as a complete sentence.
✔ I am afraid of anything that crawls: worms, beetles, caterpillars, snails, you name it.
You may capitalize the first word of the second sentence if it’s an independent clause. This rule also applies if a proper noun follows the colon.
✔ The novel has an important message: The human race needs to take care of the environment.
✔ He met the greatest American novelist at the time: Ernest Hemingway.
The Bottom Line
I hope my guide helped clear any confusion between the colon, other punctuation marks, and their correct uses.
The only way to master using colons and other punctuation marks is to practice.
You have to write daily, experimenting with various punctuation marks and their uses to find your unique style and tone in writing.