Grammar
Colons: introduce lists and explanations
You want to give the reader more information after one clear statement. A colon tells the reader that a list, explanation, or example is coming next.
Use a colon after a complete thought to introduce a list, explanation, example, or result.
Read and practice
Read the examples and try the written questions in this guide. Listening recordings are not available for this lesson yet.
Try the written questions
There is one thing to remember: check the words before the colon. /ðer ɪz wʌn θɪŋ tə rɪˈmembər: tʃek ðə wɜrdz bɪˈfɔr ðə ˈkoʊlən/
The short answer
Put a colon after a complete sentence when the next words give a list, explanation, example, or result. Do not put a colon directly after a verb or preposition when the words before it are unfinished.
The workshop needs three things: chairs, pens, and name tags.
Why it works: The words before the colon make a complete sentence. The list names the three things.
5 more examples
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One message was clear: the train would leave at six.
The second part explains what the clear message was.
Not this:One
message:was clear that the train would leave at six. What changes: The colon breaks the subject from its verb. Keep the sentence together until the complete thought ends. -
She had one goal: finish the application before Friday.
The words after the colon name the goal introduced in the first part.
Not this:She
wanted:to finish the application before Friday. What changes: Wanted needs its next words to complete the meaning, so do not separate it from them with a colon. -
Bring these items: a jacket, a bottle of water, and your ticket.
Bring these items is complete, and the colon introduces the items that the reader should bring.
Not this:
Bring:a jacket, a bottle of water, and your ticket. What changes: Bring needs an object. The phrase before the colon is not a complete thought. -
Remember this rule: the words before a colon must make a complete sentence.
The second part states the rule that the reader should remember.
Not this:
Remember:the words before a colon must make a complete sentence. What changes: Remember needs the rule as its object, so the colon is in the wrong place. -
The team chose the simplest option: meet online on Thursday.
The words after the colon identify the option chosen by the team.
Not this:The team
chose:the simplest option, meeting online on Thursday. What changes: Chose needs its object, so the colon should come after a complete statement instead.
Read the full guide
First, read the words before the colon by themselves. If they make a complete sentence, a colon may be useful. Then ask what follows. A list, a reason, an explanation, or an example can all follow a colon when they complete the reader's understanding of the first statement.
Check for a complete thought first
The most useful colon check is simple: read the words before the mark as a sentence. If they make sense alone, a colon may introduce more information. If they stop after a verb, a preposition, or an adjective that needs more words, do not add a colon there.
Our plan has one problem: the room is too small.
Our plan has one problem is complete. The words after the colon explain the problem.
Is this complete before the colon: The plan includes:?
No. Includes needs the thing that is included. Add a complete lead-in or remove the colon.
Introduce a list
A colon can introduce a list when the first part tells the reader that items are coming. Make that first part a full sentence. The list can appear in one line or in separate bullet points when the page layout needs clearer scanning.
The recipe has four main ingredients: rice, beans, tomatoes, and onions.
The sentence promises four ingredients, and the list provides them.
Choose the correct form: My bag contains: a notebook and a charger, or My bag contains two useful items: a notebook and a charger?
Use the second form. My bag contains two useful items is complete before the colon.
Introduce an explanation
Use a colon when the second part explains the first statement. The explanation may be a phrase or a full sentence. This pattern helps when you want to give a reason, identify a message, or make one point more specific.
I understood the delay at last: the road was closed after the storm.
The second part gives the reason that explains the delay.
What does the second part do in The answer was simple: we needed more time?
It explains what the simple answer was.
Use a colon before an example or result
A colon can also introduce one example or show the result of a choice. The first part must prepare the reader for that specific information. This is useful when an example is longer than a single word or when the result gives the reader the missing detail.
One local service is especially useful: the evening bus to the station.
The colon introduces the service that is the example.
Complete the sentence with a colon: We reached one decision ___ take the earlier flight.
We reached one decision: take the earlier flight. The first part is complete and the second part names the decision.
Do not split a verb from its object
Many colon mistakes happen when a writer puts the mark immediately after a verb. Verbs such as need, want, include, and bring often need an object. Keep the verb and its object together. Add a noun phrase that completes the first sentence if you want to introduce a list with a colon.
We need the following documents: a passport, a photo, and a form.
We need the following documents is a complete sentence before the list begins.
Correct this sentence: We need: a passport, a photo, and a form.
Write We need a passport, a photo, and a form, or add the following documents before the colon.
Keep the connection close
The material after a colon should develop the statement before it. Do not use a colon simply because you want a pause. If two complete sentences have an equal relationship, a period may be clearer. Choose a colon when the second part directly names, explains, or gives the result of the first.
The notice gave one instruction: return the key before noon.
Return the key before noon is the exact instruction named by the first part.
Why does the colon fit after one instruction?
The words after it state the instruction promised by the complete first sentence.
Before you go
Remember this
Use a colon to point from a complete thought to a list, explanation, example, or result. Read the words before it on their own. If they are unfinished, move the colon or remove it. This one check prevents many common colon errors.
Practice with the written examples
You can practice with the written questions in the Learn tab. Each answer includes an explanation.
Try the written questionsListening test not available yet
This lesson does not have the recordings needed for a listening test. Use the written questions in the guide to check your understanding.
Try the written questionsQuestions about "Colons: introduce lists and explanations"
What is a colon used for?
Use a colon after a complete thought when the next words give a list, an explanation, an example, or a result. In The workshop needs three things: chairs, pens, and name tags, the colon introduces the promised list.
The workshop needs three things: chairs, pens, and name tags.
Do I need a complete sentence before a colon?
Usually, yes. The words before a colon should make a complete thought. Our plan has one problem: the room is too small works because the first part can stand alone. Do not put a colon after an unfinished verb phrase.
The workshop needs: chairs, pens, and name tags.
Can I use a colon before a list?
Yes, when the sentence before it is complete and clearly introduces the list. Write The recipe has four main ingredients: rice, beans, tomatoes, and onions. Do not separate a verb such as contains directly from the items it needs.
One message was clear: the train would leave at six.
Can a colon introduce an explanation?
Yes. A colon can lead into words that explain the first statement. In One message was clear: the train would leave at six, the second part tells the reader what the message was. The two parts need a close connection.
One message: was clear that the train would leave at six.
Should I capitalize after a colon?
It depends on the style guide and what follows the colon. In ordinary sentences, a lower-case letter is common when the next words are a list or phrase. Use a capital when the following material needs one for another reason, such as a proper name.
She had one goal: finish the application before Friday.