Colon in Lists: How to Use Correctly

Summary

Use a colon to introduce a list but only after a grammatically complete sentence. Don’t use a colon after a fragment or incomplete sentence.

Examples
  • Incorrect: You will require:
    Correct: You will require the following:
  • Incorrect: The nominees are:
    Correct: The nominees are as follows:
  • Incorrect: Remember to:
    Correct: Remember three things:

Within a sentence, use a colon only at the end of a complete independent clause (one that could stand by itself as a sentence). Don’t use a colon between a verb and its object.

Example
  • Incorrect: We need: a car, a map, and the open road. (colon between verb and object)
    Correct: We need a car, a map, and the open road. (no colon at all)
    Correct: We need three things: a car, a map, and the open road. (colon after independent clause)

Don’t use a colon after a list heading, title, or caption. Prefer to use formatting options (like bold or emphasis) to set off a heading from the rest of the text.

Example
  • Incorrect: Index:
    Correct: Index

A colon may be used in a glossary to introduce a definition.

Example
  • LRR: long-range sensor

What is the colon?

The colon is a punctuation mark that directs attention to the information that follows. It is often used to introduce lists and quotations, and to amplify or explain a statement.

Examples
  • You will need three things: a needle, some thread, and a steady hand.
  • Don’t poke the dragon: it explodes!
  • Follow these steps:
    1. Find the red button.
    2. Press it.
    3. When you hear a beep, start the machine.

In this article we discuss how to use the colon correctly to introduce a list, and how this punctuation mark can be used in lists in general.

Colon to introduce a list: The general rule

Use a colon at the end of a grammatically complete sentence to introduce a list.

Examples
  • Correct: You will need the following ingredients:
    • A slice of bread
    • A pat of butter
    • A pinch of Italian seasoning
    • A slice of Parmesan cheese
  • Correct: Pack emergency supplies: a flashlight, snacks, and a good book.

Don’t use a colon if the list is introduced by a fragment or incomplete sentence.

Examples
  • Incorrect: Don’t:
    • Try to pry open the doors.
    • Panic.
    • Break the emergency phone.
  • Incorrect: The services we offer are:
    • Flight bookings
    • Hotel reservations
    • Taxi bookings
    • Holiday packages

A grammatically complete sentence comprises an independent subject, a verb, and expresses a complete thought.

Examples
  • Incorrect: The species are:
    Correct: The species are listed below:
  • Incorrect: We offer:
    Correct: We offer the following services:
  • Incorrect: Watch out for:
    Correct: Watch out for these insects:
  • Incorrect: Note:
    Correct: Note these common errors:

In horizontal lists

In a horizontal list, use a colon only at the end of a complete independent clause (one that could stand by itself as a sentence).

Example
  • Incorrect: We sell: cupcakes, cookies, and candy.
    Correct: We sell cupcakes, cookies, and candy.
    Correct: We sell confectionary: cupcakes, cookies, and candy.

In formal writing, be careful not to incorrectly insert a colon in a sentence simply to highlight a list that follows. Either omit the colon altogether, or formulate a complete independent clause, place a colon after it, and then present your list.

Examples
  • Incorrect: Bring: (1) a flashlight, (2) a book, (3) some chocolate, and (4) an extra pair of socks.
    Correct: Bring a flashlight, a book, some chocolate, and an extra pair of socks.
    Correct: Bring the following items: (1) a flashlight, (2) a book, (3) some chocolate, (4) an extra pair of socks.
  • Incorrect: Don’t forget to: turn out the lights and shut the door.
    Correct: Don’t forget to turn out the lights and shut the door.
    Correct: Don’t forget two important things: turn out the lights and shut the door.
  • Incorrect: The dragon was: smarter, stronger, and older than us.
    Correct: The dragon was smarter, stronger, and older than us.
    Correct: The dragon was impossible to beat: it was smarter, stronger, and older than us.
Tip

To identify an independent clause, check whether it can stand by itself as a sentence.

Example
  • Incorrect: We repair:
    Don’t use a colon after a fragment.
  • Correct: We repair all kinds of household appliances:
    We now have a grammatically complete sentence (subject + verb + object). It is acceptable to use a colon at the end of such a clause to introduce a list.

Don’t use a colon between a verb and its object.

Example
  • Incorrect:The services we offer include: car rental, flight booking, and hotel reservation.
    The object of the verb include is “car rental . . .” Don’t use a colon between verb and object.
    Correct: The services we offer include car rental, flight booking, and hotel reservation.
    No colon between verb and object.
    Correct: The services we offer include the following: car rental, flight booking, and hotel reservation.
    The object of the verb include is “the following,” after which the list is presented.

A colon may be used after a word or phrase that introduces a list when the verb is omitted.

Examples
  • Strengths: courage, confidence, intelligence. Weaknesses: pride, fear of public speaking.
  • Pros: safety profile, space, fuel efficiency. Cons: speed, price, availability.

In vertical lists

To introduce a vertical list using a colon, write a grammatically complete sentence followed by the colon, and then present your list. Don’t use a colon after a fragment (or incomplete sentence).

Examples
  • Incorrect: The chest contained:
    • A spade
    • A map
    • A half-eaten candle
    • A human skull
  • Correct: The chest contained four things:
    • A spade
    • A map
    • A half-eaten candle
    • A human skull
  • Incorrect: For a heavenly slice of moist chocolate cake:
    1. Find a good recipe.
    2. Buy the ingredients.
    3. Bring them together, carefully following your recipe. (You must know when to beat, when to fold, and when to just mix.)
    4. Pour the mix into a baking tray, and pop it in the oven. (Was it preheated?)
    5. Go back in time, and simply order online from us at the Quick-Cake Bakery.
  • Correct: For a heavenly slice of moist chocolate cake, follow these steps:
    1. Find a good recipe.
    2. Buy the ingredients.
    3. Bring them together, carefully following your recipe. (You must know when to beat, when to fold, and when to just mix.)
    4. Pour the mix into a baking tray, and pop it in the oven. (Was it preheated?)
    5. Go back in time, and simply order online from us at the Quick-Cake Bakery.

It is not wrong to introduce a list using a fragment. This is often done when the entire list is laid out as a complete sentence. Just remember not to use a colon to introduce such a list.

Example
  • Correct: The chest contained
    • a spade,
    • a map,
    • a half-eaten candle,
    • a human skull.
Caution

Don’t place a dash after a colon to introduce a list.

Example
  • Incorrect: To hang a painting on a wall, follow these steps:—
    Correct: To hang a painting on a wall, follow these steps:

This style of punctuation (a colon followed by a dash) is now archaic.

After headings, titles, and captions

Don’t use a colon after a list heading, title, or caption. Headings and captions are better styled using formatting options like font size, indentation, and emphasis (e.g., bold) rather than set off using a colon.

Examples
  • Incorrect: Ingredients:
    • 3 cups all-purpose flour
    • 6 eggs
    • 3 cups sugar
    • 1 teaspoon baking powder
    • 1 cup butter
  • Correct: Ingredients
    • 3 cups all-purpose flour
    • 6 eggs
    • 3 cups sugar
    • 1 teaspoon baking powder
    • 1 cup butter
  • Incorrect: Hot beverages:
    • Earl Grey
    • Assam black
    • Americano
    • Cappuccino
    • Flat white
  • Correct: Hot beverages
    • Earl Grey
    • Assam black
    • Americano
    • Cappuccino
    • Flat white

In a glossary

In a glossary or a list of definitions, use a colon to explain or define. The definition provided after the colon is usually capitalized.

Examples
  • control group: The group we did not treat but observed.
  • sum insured: The maximum amount of coverage provided under the policy.

A colon can also be used in a list of abbreviations to provide the full form of each abbreviation used in a document. Don’t capitalize the full form unless it is a proper noun.

Examples
  • PFD: portable floating device
  • SGS: small green space
  • ESA: European Space Agency

Common mistakes

Watch out for these four common mistakes when using a colon to introduce a list:

1. Don’t use a colon after a fragment or incomplete sentence.

Examples
  • Incorrect: You ordered:
    Correct: You ordered the following items:
  • Incorrect: Use a colon:
    Correct: Use a colon as follows:

2. Don’t use a colon in the middle of a clause.

Example
  • Incorrect: In the event of emergency: remain calm, proceed to the nearest exit, and leave the building in an orderly manner.
    Correct: In the event of emergency, remain calm, proceed to the nearest exit, and leave the building in an orderly manner.
    Correct: In the event of emergency, follow instructions: remain calm, proceed to the nearest exit, and leave the building in an orderly manner.

3. Don’t use a colon between a verb and its object.

Example
  • Incorrect: Please pack: a flashlight, a bar of chocolate, your favorite book.
    Correct: Please pack a flashlight, a bar of chocolate, and your favorite book.
    Correct: Please pack the following items: (1) a flashlight, (2) a bar of chocolate, (3) your favorite book.

4. Don’t use a colon after a title, heading, or caption.

Examples
  • Incorrect: Dos and Don’ts:
    Correct: Dos and Don’ts
  • Incorrect: Best Practices:
    Correct: Best Practices

Usage guide

Use a colon after a grammatically complete sentence to introduce a list. Don’t use a colon after a fragment or incomplete sentence. Also don’t unnecessarily interrupt a sentence with a colon to present a list: a colon should only appear at the end of an independent clause. One way to know you are using the colon wrong is if it appears between a verb and its object. Avoid using a colon after a caption or a heading; use formatting options instead to set off the heading from the rest of text. Finally, in glossaries and lists of definitions, a colon can be used to present the definition or meaning of a word or a phrase.

Quick Quiz

Which can be used to introduce a list?
Choose from these answers
All done!
Which is punctuated correctly?
Choose from these answers
All done!
Which is correct?
Choose from these answers
All done!
Which of these headings is punctuated correctly?
Choose from these answers
All done!

Did You Know?

Initialisms are generally capitalized.
Know more:Capital Letters in Acronyms and Abbreviations