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Let’s be honest: Punctuation can be hard. But it’s something you want to do well; how you write can make a lasting impression on your customers and clients.
The good news? There are rules you can follow to help you know when to use even difficult punctuation marks like colons and semicolons.
The bad news? There are rules you have to memorize before you’ll be able to correctly use punctuation marks like colons and semicolons.
But never fear: This article breaks down the colon, including its purpose, correct grammatical usage, and non-grammatical applications. We also explain, with practical examples, the differences between a colon (:) and a semicolon (;).
When to use a colon
The colon is used to show readers that two ideas in a sentence are closely related. It’s a punctuation mark of direction and illustration.
Probably we’re all familiar with the two equally sized vertical dots that is the colon. Most commonly, a colon follows an independent clause and tells the reader that what follows is for emphasis or explanation. However, this isn’t the only convention according to which colons are used.
One of the biggest challenges of the colon is that different style guides use them differently.
Associated Press (AP)
AP style allows you to use a colon after a sentence fragment. The word after the colon is capitalized if it’s the start of at least one complete sentence. Take for example, “The two most common adrenaline responses are: fight and flight.”
This sentence can also be written in the form of a bulleted list according to AP style.
“The two most common adrenaline responses are:
- fight
- flight”
Notice how neither of the elements in the list are capitalized because they aren’t the start of a complete sentence or proper nouns.
Chicago Manual of Style (CMOS)
The Chicago Manual of Style allows similar use as the AP, except they capitalize the first letter after the colon differently. In Chicago, you capitalize after the colon if you’re following it with two or more independent clauses.
As an example:
“John’s favorite hobbies include: Cycling on the weekend and taking long evening walks.”
The same sentence would change this way in the absence of an independent clause:
“It’s John’s favorite hobby: cycling on the weekend.”
MLA
MLA requires you to capitalize after the colon only when it introduces:
- A rule or principle
- Several related sentences
- A usually capitalized word, such as a proper noun
You shouldn’t use a colon in MLA if it introduces an example or an illustration that can instead be introduced with the help of phrases like, for example, that is, or namely.
American Psychological Association (APA) style
APA only allows you to use a colon after a complete introductory clause, i.e, a preceding part that’s a complete sentence in and of itself. As for capitalization, you only capitalize after the colon if it’s the start of at least one complete clause or a proper noun.
In-house
You may notice that our own in-house style is a modification of AP style. We like following standard AP rules except for capitalization, where we like capitalizing after the colon regardless of the clause.
If you’re looking to formulate your own guide, a good rule of thumb is that U.S.-based punctuation requires you to capitalize after the colon, whereas U.K.-based punctuation avoids that.
If all of that sounds confusing, it’s because it is. Many professionals struggle with sticking to one style guide because of how complicated the rules can be. That’s why we recommend hiring a professional freelance editor through Upwork for help!
Colon purposes
Before we dive more deeply into how to use a colon, let’s first look at their grammatical context. Some common uses of a colon include:
- Emphasis
- Dialogue
- Introduction of lists or texts
- Clarification of composition titles
Emphasis
A colon can be used to call attention to a word or phrase that comes after it, typically at the end of a sentence. In some cases, though, you’d capitalize the first word after the colon if it’s a proper noun, and depending on the style guide.
You can also use a colon to join two sentences when the second sentence emphasizes, clarifies, or explains the first sentence.
Here are a couple of examples:
- It was her favorite time of the year: Christmas.
- I love going to the movies: My favorite genres are romance and comedy.
Dialogue
If your content conveys speech, you can use a colon to separate the speaker’s name from their speech in dialogue such as in a script, legal transcript, or question-and-answer style interview. This can help with readability.
When using a colon for dialogue, your style guide and industry will determine whether or not quotation marks are used.
Here are some examples of how colons are used for dialogue:
Student: Who wrote Hamlet?
Teacher: The famous English dramatist William Shakespeare.
Q: Who wrote There and Back Again?
A: The hobbit Bilbo!
Introduce lists or texts
You can use a colon to introduce lists in place of adverbial phrases like “namely,” “that is,” and “for instance.” This isn’t, of course, a hard and fast rule. Where and how you choose to use a colon depends on the style guide you want to follow.
Here are some examples of using a colon to introduce lists or text:
- There are three major hallmarks of good writing: style, elegance, and honesty.
- She had three favorite restaurants: Red Robin, Olive Garden, and Harry’s.
Clarify composition titles
Another common use of the colon is to clarify or provide a subtitle to the main title of lectures, movies, books, and other compositions. However, the titles should convey parallel ideas and be able to stand on their own.
Some examples include:
- “Batman v Superman: Dawn of Justice”
- “The Era of Franklin D. Roosevelt, 1933-1945: A Brief History With Documents”
Non-grammatical uses of the colon
Now that you know the grammatical uses of a colon, let’s look at when and how you should use colons non-grammatically, or outside the conventions of English grammar.
Time
A colon commonly separates minutes from hours when indicating time in writing. There are no spaces on either side of the colon.
Some examples include:
- 12:20 pm
- 9:55 am
Ratio
A colon is also used between two numbers when expressing their ratios. There are no spaces preceding and following the colon.
In the example 2:1, there are 3 parts total. There might be 2 bananas and 1 orange in a fruit bowl. The ratio of bananas to oranges is 2:1.
Biblical references
When providing biblical references, a colon clarifies the verse of a specified chapter. There’s no space before or after the colon. An example would be Genesis 1:3 (which reads as “chapter 1, verse 3 of the Book of Genesis in the Bible”).
Correspondence
You may also want to use a colon after greetings or for business correspondence in business letters. This helps set apart the subject of the correspondence and the sender.
Some examples include:
- Dear Mr. Smith:
- To: Management Department
- From: Dan Jones
Page numbers (of a cited document)
Finally, you can use a colon to indicate the page numbers in a volume you’re citing as a source. This helps establish credibility because you’re showing exactly where your information came from.
Here’s an example: The Economist 9:51-67 (which means pages 51 to 67 in the 9th volume of The Economist).
Whether you’re completing a business report or thinking of starting a blog, knowing the correct uses of punctuation marks like the colon can help improve your writing.
Common mistakes and misuses of a colon
In addition to the confusion created by the rules of different style guides, colons are misused in a number of common ways.
Using a colon to separate a noun from a verb
Colons shouldn’t be placed between a noun and the verb, or between the verb and its object.
For example:
- An avid traveler, she wants to visit: Italy, Greece, and Russia. (Incorrect)
- An avid traveler, she wants to visit Italy, Greece, and Russia. (Correct)
- As an avid traveler, there are three places she wants to visit: Italy, Greece, and Russia. (Correct)
Using a colon to separate a preposition from its object
Colons shouldn’t be placed between a preposition and its object.
For example:
- He is inspired by the writings of: Hemingway, Fitzgerald, and Kerouac. (Incorrect)
- He is inspired by the writings of Hemingway, Fitzgerald, and Kerouac. (Correct)
- He is inspired by three of the most famous writers of the 20th century: Hemingway, Fitzgerald, and Kerouac. (Correct)
Using a colon after the words “including” or “such as”
You shouldn’t use a colon after words like “including,” “for example,” and “such as.” The colon—being a punctuation mark of direction, emphasis, and clarification—replaces them, and stands on its own.
For example:
- Our college is home to sculptures of famous intellectuals such as: Newton, Einstein, Goethe, and Emerson. (Incorrect)
- Our college is home to sculptures of famous intellectuals such as Newton, Einstein, Goethe, and Emerson. (Correct)
- Our college is home to sculptures of famous intellectuals: Newton, Einstein, Goethe, and Emerson. (Correct)
Capitalization and colons
Many people are often confused about whether to use a capital letter for the first word after a colon. Despite varied style guidelines (as mentioned above) on capitalization and colons, the general rule of thumb is to:
- Use a lowercase letter for the term following a colon unless the single word is a proper noun (i.e., the specific name of a particular person, place, organization, or thing) or a complete sentence for places that follow a U.K-based style—usually former colonies like India, Australia, and South Africa
- Capitalize after the colon regardless of places that follow a U.S-based style.
For example:
- He had one word for our loss: Laziness. (U.S.-based convention)
- He had one word for our loss: laziness. (U.K.-based convention)
- There was only one thing she could do: try again later. (U.K.-based)
- There was only one thing she could do: Try again later. (U.S.-based)
When to use a semicolon
The semicolon is used between independent clauses to show that two ideas are more closely related than is implied by a period, but less than a comma. It’s also used for added clarity in lists.
If this sounds very similar to the colon, that’s because it is! But while colons and semicolons are both used between clauses and in lists, their meanings are different.
But before we get into those differences, we need to talk about the semicolon in a little more detail.
Semicolon purposes
There are two common uses of the semicolon.
Separating items in a series
If a list or series already contains two or more commas, semicolons can be used to separate the elements in the list. This clarifies the sentence by making it more obvious which words go together.
For example:
The robbery witnesses included Arnold, the baker; Amy, the jewelry shop owner; and Dan, Amy’s bodyguard.
Joining two closely related sentences
You can also use a semicolon to demonstrate a relationship between two independent clauses (two sentences that can stand on their own as complete sentences). In this case, a semicolon is used in place of a period when joining sentences.
Often you can substitute a semicolon with the words “and,” “but”, “or” or “because.”
Here are some examples:
My kids love the candy store; it has all their favorite treats.
Some people prefer going to the theater for movies; others prefer watching them from the comfort of their own couch.
Common mistakes and misuses of a semicolon
The cardinal mistake when it comes to using semicolons is using them along with conjunctions. Semicolons are usually used in place of conjunctions, but in a very specific way that aims to clearly demarcate two distinct ideas that you’re trying to express. For example:
- Some people like going to the movies; but others prefer Netflix. (Incorrect)
- People looking for a weekend outing still prefer the movies; Netflix is more popular among the home watchers. (Correct)
Colon vs. semicolon
Now that we’ve discussed the basic uses of colons and semicolons, let’s look at their differences.
Both colons and semicolons are used with lists. Colons precede the list, as a way to signify that what follows adds to what came before. Semicolons are used between list items that already use commas, as a way to clear up confusion.
When used to join clauses, the colon is a mark of direction; the semicolon is primarily a mark of clarification.
A rule of thumb is to remember that colons replace ideas like “namely,” “that is,” or “for instance.” Semicolons replace conjunctions (and, but, or), and “because.”
Grammatically, only the colon can join a preceding independent clause (a sentence with a subject, a verb, and an object) with a dependent second clause (a sentence that has a subject and a verb but doesn’t express a complete thought).
In contrast, the clauses around a semicolon both have to be independent—meaning they both express a complete thought and can stand alone.
Make the most out of your writing process
English is often considered one of the most complex languages to learn; even native English speakers struggle with its many confusing grammar rules.
