# Colon (punctuation)
The colon is a punctuation mark consisting of two dots, one over the other (:), used to introduce something that explains, completes, lists, or exemplifies what comes before it in a sentence. Its core grammatical rule is that an independent clause, a group of words that could stand alone as a sentence, normally precedes it, and its central function is often summarized as "what comes next explains what came before".[1](https://www.scribbr.com/language-rules/colons/) • [2](https://aceenglishgrammar.com/colon/)
| Key fact | Detail |
|---|---|
| Core rule | The mark should follow an independent clause, a group of words that can stand alone as a sentence[3](https://our-languages.canada.ca/en/pecks-english-pointers/punct-3-pointing-the-way) |
| Main uses | Introducing lists, explanations, elaborations, quotations, and single words or phrases for emphasis[1](https://www.scribbr.com/language-rules/colons/) |
| Other uses | Separating titles from subtitles, marking time of day, ratios, and biblical or legal citations[4](https://www.oecd.org/en/publications/2025/08/oecd-style-guide-fourth-edition_c090cd0c/full-report/component-14.html) • [5](https://www.umkc.edu/mcom/docs/editorial-style-guidelines.pdf) |
| Distinctive meaning | The colon signals that the second clause expands on or explains the first; the semicolon only signals that two clauses are related[6](https://style.mla.org/colons-how-to-use-them/) |
| Spacing | No space is placed before a colon; a colon in a sentence is followed by one space, not two[4](https://www.oecd.org/en/publications/2025/08/oecd-style-guide-fourth-edition_c090cd0c/full-report/component-14.html) • [3](https://our-languages.canada.ca/en/pecks-english-pointers/punct-3-pointing-the-way) |
| Capitalization | Lowercase the first word after a colon in most styles, except for proper nouns, quotations, or titles; capitalization conventions vary by style manual[7](https://www.cochrane.org/authors/handbooks-and-manuals/style-manual/grammar-punctuation-and-writing-style/punctuation) • [8](https://uwaterloo.ca/writing-and-communication-centre/making-sense-colons) |
| Encoding | The character is U+003A COLON in the Basic Latin block of the Unicode Standard[9](https://www.unicode.org/charts/PDF/U0000.pdf) |
## Grammatical function
The colon introduces what follows it. Sheridan Baker, in *The Practical Stylist* (5th edition, 1981), put the contrast with the semicolon this way: "A colon . . . signals the meaning to go ahead; a semicolon, as in this sentence, stops it. The colon is a green light; the semicolon is a stop sign."[3](https://our-languages.canada.ca/en/pecks-english-pointers/punct-3-pointing-the-way) The distinction matters because the two marks give different readings of the same pair of statements. The [University of Sussex](https://www.edgepedia.org/university-of-sussex) punctuation guide contrasts three renderings: "Lisa is upset. Gus is having a nervous breakdown" presents two unrelated facts; "Lisa is upset; Gus is having a nervous breakdown" implies the two facts are connected in some way; and "Lisa is upset: Gus is having a nervous breakdown" explicitly makes the second statement the explanation of the first.[10](https://www.sussex.ac.uk/informatics/punctuation/colonandsemi/compared)
Like a semicolon, a colon can join two independent clauses, but it does so in a specific way: the MLA Style Center explains that a semicolon's connection may be causal, sequential, or oppositional, while a colon indicates that the second clause expands on the first, alerting the reader to read on for an explanation or expansion.[6](https://style.mla.org/colons-how-to-use-them/)
## Principal uses
**Introducing a list, explanation, or quotation.** The colon leads into a list, explanation, elaboration, or indented quotation, and in most such cases is preceded by an independent clause.[4](https://www.oecd.org/en/publications/2025/08/oecd-style-guide-fourth-edition_c090cd0c/full-report/component-14.html) It can add emphasis to a single word or phrase, as in "She asked for only one thing: understanding," and it can introduce a quotation.[1](https://www.scribbr.com/language-rules/colons/) A colon is preferred over a comma when a quotation runs to two or more sentences or when the introduction is formal.[2](https://aceenglishgrammar.com/colon/) It is also used after the salutation in formal business correspondence, as in "Dear Sir or Madam:".[11](https://writingcommons.org/section/grammar/mechanics/punctuation/colons/)
**Conventional and technical uses.** Beyond sentence grammar, the colon appears in fixed formats: time of day (7:30 a.m.), elapsed time (1:25:01.7), ratios such as an 18:1 student-to-teacher ratio, and biblical or legal citations such as 2 Kings 21:4.[5](https://www.umkc.edu/mcom/docs/editorial-style-guidelines.pdf) • [2](https://aceenglishgrammar.com/colon/) It separates titles from subtitles, as in *Global Trends in Government Innovation 2024: Fostering Human-Centred Public Services*.[4](https://www.oecd.org/en/publications/2025/08/oecd-style-guide-fourth-edition_c090cd0c/full-report/component-14.html)
## Common errors
The most frequent mistakes occur when a colon is placed inside an independent clause instead of after it, breaking an essential grammatical connection. The Canada.ca guide's examples include a colon separating a preposition from its object ("without: the buzzing in the speakers"), a verb from its object, and a verb from its subject complement; in each case omitting the colon corrects the sentence.[3](https://our-languages.canada.ca/en/pecks-english-pointers/punct-3-pointing-the-way) A related rule: a colon should not be used to introduce words that fit properly into the grammar of the sentence without it, so "My favorite foods are: sushi, pizza, and nachos" is incorrect because the list is the complement of the verb.[12](https://vle.seu.ac.lk/pluginfile.php/2013/mod_resource/content/0/The%20Handbook%20of%20Good%20English.pdf) • [8](https://uwaterloo.ca/writing-and-communication-centre/making-sense-colons)
Style guides also advise restraint. The OECD style guide says to use colons sparingly because overuse reduces readability, forbids more than one colon in a sentence, and forbids a space before a colon.[4](https://www.oecd.org/en/publications/2025/08/oecd-style-guide-fourth-edition_c090cd0c/full-report/component-14.html)
## Capitalization and spacing
Conventions differ. Cochrane's style manual follows a colon with a lower-case letter unless the next word must start with an upper-case letter, such as a proper noun or acronym.[7](https://www.cochrane.org/authors/handbooks-and-manuals/style-manual/grammar-punctuation-and-writing-style/punctuation) The OECD guide forbids capitalizing the first word after a colon except for titles.[4](https://www.oecd.org/en/publications/2025/08/oecd-style-guide-fourth-edition_c090cd0c/full-report/component-14.html) Other guides allow capitals when the colon introduces a quotation or formal statement, or when what follows consists of complete sentences.[11](https://writingcommons.org/section/grammar/mechanics/punctuation/colons/) • [13](https://cla.umn.edu/style-guide/punctuation) The University of Waterloo notes that capitalization of the first word after a colon joining two complete sentences varies according to the style manual used.[8](https://uwaterloo.ca/writing-and-communication-centre/making-sense-colons) French usage differs from English: French inserts a space before a colon.[14](https://blogs.kent.ac.uk/skepsi/files/2009/12/style-guide-8th-edition.pdf)
## History
Punctuation began as a guide to speech rather than grammar. Early punctuation marked pauses of different lengths on delivery, and the mark that would become the colon originally indicated a pause between elements whose sense is complete even though the sentence is not.[15](https://time.com/5779281/punctuation-history/) The colon itself is of Greek origin, but the practice of writing it with two dots is credited to Latin authors or perhaps the early printers of Latin books.[16](https://en.wikisource.org/wiki/The_Grammar_of_English_Grammars/Part_IV/Chapter_I) Register affects frequency: formal academic prose makes more use of colons, semicolons, and brackets than conversational or journalistic prose, and the *Handbook of Good English* describes the colon as "a rather formal stop, to be used sparingly".[17](https://documents.manchester.ac.uk/display.aspx?DocID=14044) • [12](https://vle.seu.ac.lk/pluginfile.php/2013/mod_resource/content/0/The%20Handbook%20of%20Good%20English.pdf)
## Colon, semicolon, and dash compared
The three marks overlap but are not interchangeable. Colons introduce or explain; semicolons join two closely connected independent clauses or divide complicated entries in a list; dashes allow more flexibility and are usually less formal, signaling a break, a remark, or stress.[18](https://grammarchecklist.com/en/advanced-c1/punctuation-colon-semicolon-dash-conventions) A dash can substitute for a colon when introducing a list, and in formal writing a colon is usually preferred to a dash when the second clause summarizes or explains the first.[19](https://philology.science/academic_writing/rules/97.html)
## References
1. [Amy Luo. When to Use a Colon (:) | Rules, Guide & Examples, Scribbr (revised July 19, 2023)](https://www.scribbr.com/language-rules/colons/)
2. [Simon Avery. The Colon in English: Rules, Uses, Examples and Errors, Ace English Grammar](https://aceenglishgrammar.com/colon/)
3. [Peck's English Pointers: Pointing the way: Colons and semicolons, Language Portal of Canada](https://our-languages.canada.ca/en/pecks-english-pointers/punct-3-pointing-the-way)
4. [Punctuation, OECD Style Guide (Fourth Edition)](https://www.oecd.org/en/publications/2025/08/oecd-style-guide-fourth-edition_c090cd0c/full-report/component-14.html)
5. [UMKC Editorial Standards Manual, section 3.5 Grammar and Punctuation](https://www.umkc.edu/mcom/docs/editorial-style-guidelines.pdf)
6. [Erika Suffern. Colons: How to Use Them, MLA Style Center](https://style.mla.org/colons-how-to-use-them/)
7. [Punctuation, Cochrane Style Manual](https://www.cochrane.org/authors/handbooks-and-manuals/style-manual/grammar-punctuation-and-writing-style/punctuation)
8. [Making Sense of Colons, Writing and Communication Centre, University of Waterloo](https://uwaterloo.ca/writing-and-communication-centre/making-sense-colons)
9. [The Unicode Standard, Version 18.0, C0 Controls and Basic Latin chart](https://www.unicode.org/charts/PDF/U0000.pdf)
10. [The Colon and the Semicolon Compared, University of Sussex](https://www.sussex.ac.uk/informatics/punctuation/colonandsemi/compared)
11. [Colons, Writing Commons](https://writingcommons.org/section/grammar/mechanics/punctuation/colons/)
12. [The Handbook of Good English, section 2-16 Punctuation](https://vle.seu.ac.lk/pluginfile.php/2013/mod_resource/content/0/The%20Handbook%20of%20Good%20English.pdf)
13. [Punctuation, College of Liberal Arts Style Guide, University of Minnesota](https://cla.umn.edu/style-guide/punctuation)
14. [Style Guide (8th edition), University of Kent](https://blogs.kent.ac.uk/skepsi/files/2009/12/style-guide-8th-edition.pdf)
15. [The History and Origins of Punctuation Marks, TIME](https://time.com/5779281/punctuation-history/)
16. [The Grammar of English Grammars, Part IV, Chapter I, Wikisource](https://en.wikisource.org/wiki/The_Grammar_of_English_Grammars/Part_IV/Chapter_I)
17. [Handbooks, University of Manchester](https://documents.manchester.ac.uk/display.aspx?DocID=14044)
18. [Punctuation: colon/semicolon/dash (conventions), Grammar Checklist](https://grammarchecklist.com/en/advanced-c1/punctuation-colon-semicolon-dash-conventions)
19. [Consider separating the clauses with a semicolon, colon, or dash, Philology](https://philology.science/academic_writing/rules/97.html)
---
*Topic: Encyclopedia › Society and history › Languages and linguistics › Writing and notation systems › Punctuation and orthographic marks*
*Initially written Sep 17, 2026 · Reviewed: Oct 25, 2026 · Edited: Oct 15, 2026; Oct 25, 2026 · Last review: Oct 25, 2026*
*Copyright 2026 EdgeChat AI, a subsidiary of Biostate AI.*
License: Edgepedia Community License 1.0, https://www.edgepedia.org/edgepedia/license