Everywhere I look, I seem to be finding examples of colons being used after a single word.

The dog is brown.
The cat is white."

"Recommended: Take this twice a week.
Not recommended: Take this twice a day."

Start at 5
Add 7 each time"

My understanding is that a colon should be used only after a full sentence, and that following a colon you can have a sentence fragment. I'm not convinced that this could be justified as inverting the construction, but I'm happy to be told otherwise...

What I'm really looking for is a reference that justifies this usage or shows it to be wrong so I have a concrete rule to follow before huge amounts of material get written wrongly. I've tried every grammar/punctuation book I can find in my office, as well as multiple google searches, and even on pages listing the uses of colons (e.g. this page) this layout is used, but not covered as a rule! Is this just something that is so commonly used by people that it's become accepted?

  • 5
    Isn't everything in English 'just something that is so commonly used by people that it's become accepted'? I have collected articles etc spewing out plenty of 'rules' about how colons 'should be used'. They don't all agree. // This Wikipedia article is sane and balanced. If contentious. Jul 20, 2016 at 9:49
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    Related: Colon after Destination
    – TrevorD
    Jul 20, 2016 at 11:30
  • 2
    Hypothesis: The meatbags' language is broken.
    – ZAD-Man
    Jul 20, 2016 at 17:42

7 Answers 7


To build on the point that @BladorthinTheGrey is making, grammar describes the way words are related to form meaning in sentences. But there are other ways to form relationship that express meaning, including page layout devices such as labels or headings, or parallel constructions such as tables.

A word (or a few words) followed by a colon is a common way of attaching a label to a piece of information. This is one of those non-grammatical uses referred to in other answers, and it is non grammatical because it is outside the scope of grammar. (That is, not concerned with the construction of sentences.)

So, Examples: is a label in the example given. It is a common and accepted way to create labels, but it is outside the scope of grammar because it is not part of a sentence construction.

  • I completely agree with your answer, but I can understand why the O.P. is a bit consternated, especially since punctuation guides or readily delve into other non-grammatical uses of the colon (John 3:16, 3:16 PM, 3:16 odds, etc.)
    – J.R.
    Jul 21, 2016 at 9:21
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    I've taken the liberty of making a minor amendment because your use of "above" depends on sort order of answers & the current 'scores'.
    – TrevorD
    Jul 22, 2016 at 14:12

Below is a copy of an extract from The Punctuation Guide relating to the various uses of a colon.

  1. You will see, at the bottom of the first section "Introducing a list" are examples of usage after a single word: "Correct: …" & "Incorrect: …".

  2. Similar usage is also shown in the last section "Correspondence", with a colon being used after a single word or brief 'title'.

  3. The usage you've referred to as "after a full sentence" is illustrated in the sections "Between independent clauses …" & "Emphasis"

enter image description here enter image description here enter image description here enter image description here

From: http://www.thepunctuationguide.com/colon.html

Further information is also given in my answer to this related question: Colon after 'Destination'

  • This answer doesn't address the asker's question or specific examples, beyond providing more examples. An actual answer to this question needs to either cite a grammatical reference explaining whether the structures explicitly mentioned in this question are valid or not, or else perform some statistical analysis to suggest they're common enough to be considered normal.
    – talrnu
    Jul 20, 2016 at 14:39
  • @talrnu Q is entitled "Colons after a single word" & asks for "a reference that justifies this usage". You say an "answer ... needs to ... cite a grammatical reference". But the question is not about grammar: it is about punctuation; so I have cited a reference that outlines the correct usage of punctuation. Paras 1 & 2 of my answer specifically point to the sections of the cited reference addressing that issue. What more do you want?
    – TrevorD
    Jul 20, 2016 at 14:48
  • @talrnu Additionally, two other answers also refer to the same citation: are you suggesting we are all wrong. Maybe you should write your own answer instead of attacking other answers.
    – TrevorD
    Jul 20, 2016 at 14:54
  • You have it backwards - if everyone cites the same source, that makes the collection of answers less valuable than if they each cited different sources. You're also ignoring my point: the cited reference does not address the examples in the asker's question, which in this particular question are the focus of the asker's concern. I'm not attacking anyone, I'm pointing out failure, don't take it personally. I don't need to create my own answer, other people have already provided acceptable answers; I've upvoted these.
    – talrnu
    Jul 20, 2016 at 15:46
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    @TrevorD Oh, sorry not you, the image uses it in Incorrect: The bookstore specializes in: ... Jul 20, 2016 at 23:03

According to this guide, colons can be used for emphasis:

The colon can be used to emphasize a phrase or single word at the end of a sentence.

Conclusion: This practice can be followed when that single word is at either end of the sentence.

  • I note that your link refers to The Punctuation Guide. Apologies: I had already included it in my answer before checking the link in your answer!
    – TrevorD
    Jul 20, 2016 at 12:17
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    "The end of a sentence" does not equate to "either end of the sentence". The examples at the link you provide do not support your claim, either.
    – talrnu
    Jul 20, 2016 at 14:36
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    @talmu - One of the two examples at the linked website reads: Five continents, three dozen countries, over a hundred cities: this was the trip of a lifetime. It is clear that Five continents, three dozen countries, over a hundred cities is not a complete sentence, yet this was the trip of a lifetime is. Since the rule being discussed is The colon can be used to emphasize a phrase or single word at the end of a sentence, I've concluded that this phrase (or word) can be at the beginning of the sentence as well. Otherwise, the example doesn't agree with the rule.
    – J.R.
    Jul 20, 2016 at 14:47
  • @J.R.: Which part of the sentence is being emphasised? To my mind it's the "...trip of a lifetime" part that receives the emphasis...
    – psmears
    Jul 20, 2016 at 17:41

When you're writing formal text, you generally write in full sentences. No sentences fragments: those are forbidden in formal writing. In this context, colons should only be used after full sentences. If you put a colon after a sentence fragment, it's still a sentence fragment. But it's not any worse than a sentence fragment with no colon.

But there are lots of times when people aren't writing formal text, and they feel it's acceptable to use sentence fragments. In these cases, this restriction on the use of the colon no longer applies.


The Wikipedia article: Colon_(punctuation) gives (reformatted; I've italicised the most relevant comments) a good overview of the uses and conditions of use of the colon:

The most common use of the colon is to inform the reader that what follows the colon proves, explains, defines, describes, or lists elements of what preceded it. [It elaborates on what comes before the colon.]
In modern American English usage, a complete sentence precedes a colon, while a list, description, explanation, or definition follows it. The elements which follow the colon may or may not be a complete sentence: since the colon is preceded by a sentence, it is [conventionally regarded as] a complete sentence whether what follows the colon is another sentence or not. While it is acceptable to capitalize the first letter after the colon in American English, [this] is not [usually considered to be] the case in British English.

colon used before list

Williams was so hungry he ate everything in the house: chips, cold pizza, pretzels and dip, hot dogs, peanut butter and candy.

colon used before a description

Jane is so desperate that she'll date anyone, even Tom: he's uglier than a squashed toad on the highway, and that's on his good days.

colon before definition

For years while I was reading Shakespeare's Othello and criticism on it, I had to constantly look up the word "egregious" since the villain uses that word: outstandingly bad or shocking.

colon before explanation

I had a rough weekend: I had chest pain and spent all Saturday and Sunday in the emergency room.

Some writers use fragments (incomplete sentences) before a colon for emphasis or stylistic preferences (to show a character's voice in literature), as in this example:

Dinner: chips and juice. What a well-rounded diet I have.

I'm sure that all the (four) listed types of use here have been used in at least less formal writing, for dramatic effect or conciseness.

The colon is also used in what The Punctuation Guide (J.R.'s link above) calls 'non-grammatical' ways (in registers where insistance on formal grammar would be silly), which include:

The colon is frequently used in business and personal correspondence.

Dear Ms. Smith:

cc: Tom Smith

Attention: Accounts Payable

PS: Don’t forget your swimsuit.

But 'non-grammatical' doesn't mean ungrammatical / unacceptable.


In these examples the words that are followed by colons are subtitles so following with a colon to show a list is perfectly acceptable. This example:

Examples: The dog is brown. The cat is white.

is such a usage, it has provided a list of examples after the subtitle Examples.

Anyway, as @EdwinAshworth points out, pretty much everything in English is just something that is so commonly used by people that it becomes accepted, that's how language evolves.


As stated in this article: "Of course, we frequently use colons after phrases when they are used as headings--such as after the words To, From, and Date in a memo--but here in this tip we are talking about the proper use of the colon in running text," the examples you mentioned above can be interpreted as "colons after headings."

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