What is a Colon

Colons Video

When writing, using punctuation is important to make sure that our ideas are conveyed clearly and accurately to the reader. What punctuation we use and its placement between words can completely change the meaning of a sentence. In today’s video, we’ll be looking at colons, seeing what they do and when to use them. Let’s get started!

One of the most common ways colons are used in writing is to signify the start of a list or sequence of things in a sentence. Here’s an example:

In a deck of cards, there are four different suits: spades, hearts, aces, and clubs.

In this example, notice the placement of the colon – it is right after the word suits, and directly after it, we see a list of the different types of suits in a deck of cards. Remember when using a colon to emphasize a list of things, the phrase preceding the colon MUST be a complete sentence that stands alone, otherwise known as an independent clause. “In a deck of cards, there are four different suits”, is an independent clause, so this colon was correctly used. How about this one?

In a deck of cards, the four different suits are: spades, hearts, aces, and clubs.

This example doesn’t use the colon correctly, because its placement interrupts the flow of the sentence. You’ll notice that “In a deck of cards the four different suits are” is not a complete sentence or independent clause, so we definitely know this colon was not used correctly.

Adding a colon to a sentence can also be used to emphasize the information preceding it. In this case, the independent clause after the colon must directly relate to the independent clause before it – here’s an example:

The doctor reached a diagnosis: the patient had a lethal virus.

In this example, the independent clause after the colon is directly related to the independent clause before it. It gives more details about the doctor’s diagnosis and explains to us what it is. Let’s look at a longer sentence:

Mark knew what he had to do: He would first ask his boss for a raise. If that didn’t work, he would quit his job.

In this example, we see that the colon separates one independent clause from two complete sentences. The sentences after the colon support the clause before the colon. When there are two or more sentences after a colon, remember to capitalize the first letter of the word that comes directly after the colon, which in this case is He.

Colons can also emphasis a single word or phrase at the end of a sentence – for example:

After the fierce battle, the warrior was known by all as one thing: a hero.

Here, the phrase a hero emphasizes the clause before the colon by describing the warrior.

So, we’ve looked at several examples of colons being used correctly, but it’s a common mistake for writers to use a colon in a place that incorrectly separates parts of speech in the sentence. A colon should never separate:

  • A noun from its related verb
  • A verb from its object or subject complement
  • A preposition from its object
  • Or the subject from its predicate

Here’s an example of a common mistake.

The three primary colors are: red, yellow, and blue.

In this example, the colon separates the verb are from the objects red, yellow, and blue – this is not appropriate colon usage. Here’s another example:

When going to a job interview, you should never do things such as: be late, come unprepared, or wear wrinkled clothes.

In this example, the colon separates two incomplete sentences. Remember, a colon may separate two independent clauses or an independent clause from a phrase. Here, “When going to a job interview, you should never do things such as” is not a complete thought. Don’t let common phrases like such as, including, or the following trick you into thinking the colon is in the right place. It always has to be a complete thought before and after the colon.

Before we go, let’s review with a practice question:

The jury knew he was guilty the evidence was overwhelming.

What is the correct placement of the colon in this sentence?

  1. After the word was
  2. After the word knew
  3. After the word he
  4. After the word guilty

The correct answer is D.

Thanks for watching, and happy studying!


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by Mometrix Test Preparation | This Page Last Updated: February 17, 2023