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Punctuation—Hyphens and Dashes

Summary:

These resources provides guidelines for using punctuation in your writing.

Contributors:Tony Cimasko
Last Edited: 2013-03-22 08:43:43

Hyphens (-) are used to connect two or more words (and numbers) into a single concept, especially for building adjectives.  Likewise, some married women use hyphens to combine their maiden name with their spouse’s name:

They are also a necessary component of the numbers 21 through 99:

Although they can be used as substitutes for the word “to” when discussing value ranges and scores in games, it is better to use the word in formal writing situations than the punctuation:

Hyphens are also used in syllable breaks when words cannot fit completely on a line, and must be continued on the following line.  With word processors and the ability to automatically move whole words, though, this has become less common:

Dashes (—) can be used to indicate an interruption, particularly in transcribed speech:
The chemistry student began to say, “An organic solvent will only work with—” when her cell phone rang. 

They can also be used as a substitute for “it is, “they are,” or similar expressions.  In this way they function like colons, but are not used for lists of multiple items, and are used less frequently in formal writing situations:

They can also be used as substitutes for parentheses:

Note that dashes are double the length of hyphens.  When you type two hyphens together (--), most word processors automatically combine them into a single dash.
The Purdue OWL maintains a number of resources on punctuation you can visit to learn more:

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