Colon (punctuation): Difference between revisions
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A '''colon''' is a mark consisting of two points arranged vertically (:). As a [[punctuation mark]] it is used in many languages. It is also used in [[mathematics]] to show [[ratio]]s: a ratio of five to four can be written 5:4. | A '''colon''' is a mark consisting of two points arranged vertically (:). As a [[punctuation mark]] it is used in many languages. It is also used in [[mathematics]] to show [[ratio]]s: a ratio of five to four can be written 5:4. | ||
==Punctuation mark== | ==Punctuation mark== | ||
Like a [[full-stop]] ([[British English]], known as a period in [[American English]]), a colon can follow a grammatically complete utterance. The same is true of the [[semi-colon]]. | |||
Like a [[full-stop]] ([[ | |||
(In the case of the full stop/period the complete phrase is called a [[sentence (grammar)|sentence]].) | (In the case of the full stop/period the complete phrase is called a [[sentence (grammar)|sentence]].) | ||
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to indicate proportion (2 : 4 = 1 : 2) | to indicate proportion (2 : 4 = 1 : 2) | ||
or division (or ratio: 2 : 4 = 0.5). | or division (or ratio: 2 : 4 = 0.5). | ||
Revision as of 20:53, 19 February 2010
A colon is a mark consisting of two points arranged vertically (:). As a punctuation mark it is used in many languages. It is also used in mathematics to show ratios: a ratio of five to four can be written 5:4.
Punctuation mark
Like a full-stop (British English, known as a period in American English), a colon can follow a grammatically complete utterance. The same is true of the semi-colon. (In the case of the full stop/period the complete phrase is called a sentence.)
Unlike the full-stop and semi-colon, which merely mark an ending, a colon points forward, 'delivering' what is promised before it:
- I have something to tell you: you were right after all.
Colons are usually taught to children as introducing lists, and this is a typical function:
- Don't forget:
The colon is not usually followed by a capital (uppercase) letter without a line-break: not usually. The exception is where it is introducing a quotation where inverted commas are not used, the capital letter obviating the need for them, as in a headline:
- Smith: The situation is no longer sustainable.
Or play:
- HAMLET: To be or not to be, that is the question.
Spacing
As a punctuation mark, one increasingly sees the colon used with a space on either side, as there exist options for this to occur automatically on some processors (and it is a habit in texting). But in most languages, although not in French, this is not considered correct, and the colon should be used without a space before, exactly like other punctuation marks, the informal use of a hyphen as a dash - like this - being the only exception.
The spacing option is intended to be used in such examples as:
- pound : euro = 1.1311
For in this case the colon is not used as a punctuation mark, but as a mathematical symbol for a binary operation (such as the plus sign "+") to indicate proportion (2 : 4 = 1 : 2) or division (or ratio: 2 : 4 = 0.5).