Colon

A colon is a punctuation mark most commonly used to introduce dialogue, lists, or texts. The colon appears as two dots arranged one above the other. A colon is similar to a semicolon and is often incorrectly used as one, but the punctuation marks serve different grammatical purposes. Colons are also used to add clarity to titles, to write numeric representations of times and ratios, and in Bible verses.

Background

Various types of punctuation involving dots have been used since the days of the Ancient Greeks. In the Middle Ages (500 CE–1500 CE), the sheet music for the Gregorian chants sung by Catholic monks used a mark called the punctus elevates, which is Latin for “elevated point.” It indicated the length of time that the singers should pause. In the 1600s, this punctuation mark was applied to other written text to indicate a pause that was longer than a comma but not as long as a period. The word “colon” comes from a Greek word that means “limb” or “member,” but it is unclear how the term came to be used as a punctuation mark.

Overview

A colon appears as two equally sized dots aligned above each other. It is similar in appearance to a semicolon, which is a dot above a comma. However, the punctuation marks are not interchangeable. A semicolon is used to separate long items in a series. For example, “The players involved were John Smith, pitcher; Dan Jones, first baseman; and Sam Johnson, left fielder.” The semicolon is also used to separate two closely related independent clauses, as in “She studied hard; she knew her future depended on her exam grade.”

Most of the colon’s uses indicate some connection between the sections of text it separates. For example, a colon can be used to introduce and add emphasis to additional information, as in the sentence, “He knew exactly what he wanted to buy: a new phone.” In this case, the text after the colon is not capitalized. However, if this text begins with a proper noun or starts a complete sentence, it should be capitalized, as in “Recycling containers should be placed at all entrances: They encourage the responsible disposal of materials that can be recycled and reused.”

A colon may be used to introduce quotes, as in, “Mom always said: ‘Eat your veggies’.” Colons are commonly used to introduce lists, as in “The car needed work: new brakes, tires, and a replacement headlight.” They can also add clarity to dialogue. For example, “Reporter: What is the most important issue for voters? Candidate: Rising costs.”

Another use for colons is clarifying the titles of books, articles, and other works. They do this by combining two parallel ideas, such as “The title of her report was ‘Water: Essential Fluid for Life’.”

Colons are used in other ways as well. They are used when writing a time of day, as in “School starts at 8:00 a.m.” Colons are used in Bible verses to separate chapters from verses, such as Genesis 8:1. Ratios also use colons to indicate the relationship between components. For example, “The formula mixed water and salt 2:1.”

Bibliography

“Colon.” Punctuation Guide, www.thepunctuationguide.com/colon.html. Accessed 10 Nov. 2023.

“The Colon.” University of Sussex, www.sussex.ac.uk/informatics/punctuation/colonandsemi/colon. Accessed 10 Nov. 2023.

O’Reilly, Anthony. “When to Use a Colon, With Examples.” Grammarly, 25 Apr. 2023, www.grammarly.com/blog/colon-2/. Accessed 10 Nov. 2023.

“Punctuation: Colon and Semicolon.” Western Michigan University Writing Style Guide, wmich.edu/writing/punctuation/colon. Accessed 10 Nov. 2023.

Stuart, Lynn. “A History of Punctuation: The Colon.” English Speaking Union Scotland, 10 Jan. 2018, esuscotland.org.uk/a-history-of-punctuation-the-colon/. Accessed 10 Nov. 2023.

Timms, Ashley. “A History of Punctuation in English.” Unravel Magazine, 28 Dec. 2016, unravellingmag.com/articles/history-punctuation-english/. Accessed 10 Nov. 2023.