Hyphens, en dashes, and em dashes have their places in a sentence. Often, they are used interchangeably, and they are not intended to be used that way. They each have a particular purpose. The use of hyphens and dashes can be somewhat confusing.
Most writers are very familiar with using hyphens, since they are the most frequently used. It’s the smallest of the three, with the en dash slightly longer, and the em dash slightly longer than the en dash. If you’re using Microsoft Word, you can find the en dash and the em dash under the “Insert” tab under “Symbols.” From there, you can make a shortcut to those symbols so you can just use your keyboard the next time you need it; this is what I prefer to do. That way when you are typing, you can just use your shortcut on the keyboard instead of going to the symbol menu each time you need it.
Hyphens are used in compound words and for dividing words. They are also used to separate numbers, like phone numbers and social security numbers. See the following examples:
1-800-123-4567 (phone number)
“The way I spell that is F-E-R-G-U-S-O-N.”
He lives in a middle-class neighborhood.
She has a three-year-old boy.
(Please note that there are several different rules for compound words and whether or not to use the hyphen.)
Typically, you can use en dashes to connect numbers. Rarely are they used to connect words, and that is usually only with connecting two compound words. In British English, it is used as a dash for interruption in a sentence, usually dialogue, or setting off a phrase more strongly than using commas. There would be a space either side of the en dash.
Refer to pages 12–24
a hospital–nursing home connection
“She walked away – or rather, ran away – from the laughing crowd.”
Em dashes have several different uses. Most frequently, they are used to amplify or set apart aspects of a sentence.
“She walked away—or rather, ran away—from the laughing crowd.”
“Is he—will he—accept the position?” (You could also use ellipses here.)
You can also use the em dash to indicate sudden breaks in dialogue.
“I’m sorry; I tried to—”
“Trick me?” she demanded.
To recap: the hyphen is the shortest, the en dash is slightly longer (named for being about the same length as a typed letter n), and the em dash is the longest of the three (named for being about the same length as a typed letter m).
Originally posted 5/4/2009 and happily updated 11/14/2017. Thanks for reading!