Colon

1. What is a Colon?

A colon (:) is a type of punctuation that comes before an explanation, description, definition, or list. In modern English writing, a colon follows an independent clause, and is then followed by something that answers or explains that clause.

A good way to think about colons is that they lead to more information or tell the reader that more details are coming in the sentence.

2. Examples of a Colon

There are lots of great ways to use colons to strengthen your writing. Here are some examples of how they fit in sentences:

Sally plays three sports: softball, soccer, and tennis. List
I didn’t eat the sandwich: it had way too much mayo. Explanation
She hated the team’s jerseys: brown and red with purple stripes. Description
My neighbor has a “green thumb”: excellent gardening skills. Definition

3. Main Ways to Use Colons

Colons can be very important and useful tools in writing. They can emphasize certain points or details, build up anticipation in a sentence, explain something in a more descriptive way, and even just help make a sentence clear. Accordingly, we use them for a few main things, like giving explanations and descriptions and sharing definitions and lists.

As mentioned, a colon precedes the list or explanation that comes after an independent clause. But, whatever comes after the colon doesn’t need to be a full sentence—it can be a dependent clause, a list, a phrase, and so on. So, a sentence with a colon generally follows the form Independent Clause + Colon + list/description/explanation

a. For Explanations

Colons are great for providing explanations of situations and to provide further context in sentences. In this form, whatever comes after the colon explains what precedes it. Here are some examples:

I’m supposed to graduate next week, but there’s one problem: I failed gym.
There was only one solution: I would have to go to summer school.
Math is such a hard subject: if you don’t follow the rules, you can’t find the answer!
Sally wouldn’t be pitching this game: she sprained her shoulder over the weekend.

b. For Descriptions

To make a sentence more descriptive, you can add a colon followed by details about the sentence’s subject. This technique lets your sentences be more interesting and informative, like these examples:

Everyone loved the school’s mascot: a shining warrior sitting on top of an armored horse.
The waffles were amazing: crispy on the outside, soft on the inside, and drowning in butter and maple syrup.
I couldn’t believe her outfit: striped pants, plaid tank top, polka jacket and a rainbow socks!
It’s easy to describe the old school busses: smelly, sticky, rickety and slow!

c. Before a Definition

We often identify a word or term in a sentence, and then follow it with a colon and a definition for that word to help share its meaning with readers. Here are some examples:

I had to look up “arachnophobia” in the dictionary: the fear of spiders.
The psychology book explained the term “phobia”: an irrational fear of something.
I have my own definition of “spider”: the scariest creature on planet Earth.

d. For Lists

Perhaps one of the most popular and simple ways to use a colon is to share lists. We use lists all the time—to share a defined number of things, for examples, and even just for details. Colons help us do that with clarity. Here are some ways to write lists after colons:

All students are required to take five classes: math, science, English, history, and music.
The exam will have several types of questions: multiple choice, true or false, short answer and an essay.
I had quite a big breakfast today: eggs, home fries, toast, bacon, sausage, pancakes, and fruit salad, and a glass of orange juice.
I have three ways to get to school: walking, biking, or taking the bus.

4. Other Ways to Use Colons

There are some minor, more technical things in writing that we need colons for; mainly for providing clarity. Here are five ways we do so.

a. When writing a letter or email, particularly one that is formal, you can use a colon at the end of a greeting:

To Whom It May Concern:
Dear Sir or Madam:
To the Parents and Students of Springfield Middle School:

b. When writing the time, American English uses a colon to separate the hours and minutes:

I have a doctor’s appointment at 10:00.
I wake up each day around 8:30.
I usually eat lunch around 1:30 in the afternoon.

c. For some literary references, particularly the Bible, we need to use colons to show location in the text:

John 1:3
Genesis 1:27
1 Corinthians 13:4-8

d. We can use colons for certain titles of films and literature that have subheadings or secondary names:

Lord of the Rings: The Fellowship of the Ring
Star Wars Episode VI: The Return of the Jedi
The Twilight Saga: Breaking Dawn

e. Colons also help show the speaker within a dialogue in literature:

Sally: I have so much homework.
Jane: Why didn’t you do it during study hall?
Sally: I planned to, but Sam kept texting me!

5. How to Avoid Mistakes

Colons are always the best option when you’re about to share a list or explanation, so long as you use them correctly. But, people often make mistakes that can really mess up a sentence’s grammar, like putting them between objects and verbs or between other words that need to go together. Basically, it shouldn’t come in the middle of an independent clause or between parts of an independent clause—it should go after!

When in doubt, it’s usually better to leave a colon out, rather then misuse it. Here are some rules that you should always follow to avoid creating grammar problems with colons:

A colon doesn’t come between a subject and its predicate:

Today, Sally: will go to school, play soccer, and study. INCORRECT
Today Sally will do three things: go to school, play soccer, and study. Correct!

Here, a colon shouldn’t separate the subject “Sally” from the predicate “will go.”

A colon doesn’t come between a verb and its objects:

The three primary colors are: red, blue, and yellow. INCORRECT
There are three primary colors: red, blue, and yellow. Correct!

Here, there shouldn’t be a colon between the verb “to be” (“are”) and the colors.

A colon doesn’t come between an object and its preposition:

Sally has played soccer in: New York, Florida, and Ohio. INCORRECT
Sally has played soccer in New York, Florida, and Ohio Correct!
Sally has played soccer in several states: New York, Florida, and Ohio. Correct!

Here, there shouldn’t be a colon between the preposition “in” and the locations.

A colon isn’t necessary after words or phrases like “such as” and “for instance”:

Jane plays a lot of sports, such as: soccer, tennis, and basketball. INCORRECT
Jane plays a lot of sports, for instance: soccer, tennis, and basketball. INCORRECT
Jane plays a lot of sports: soccer, tennis, and basketball. Correct!

In addition to these rules, overall, remember this simple thing: colons precede lists and explanations to show that they are coming!