There are two types of dashes in Standard American English: the em dash, en dash.
Em dash ( — ), En dash ( – )
The em dash ( — ) is twice as long as the en dash, and its grammatical usage is more complex. An en dash ( – ) is mostly used to indicate a range of numbers.
Em Dash ( — )
The em dash is twice as long as the en dash. Em dashes emphasize parts of a sentence more emphatically than commas. The em dash is used to indicate a break in thought or sentence structure. An em dash can be used to introduce a phrase added for emphasis, definition, or explanation. It can also be used to separate two clauses. There should be no space on either side of the em dash.
- I only wanted a piece of pie—but the waitress talked me into a steak!
- I would request—or should I say, insist—that anyone planning on drinking at the party bring a designated driver.
- All sixty-nine members of the Shady Grove Homeowners’ Association—even the newly appointed president—voted to increase the annual membership dues.
- The mayor—a man of low energy, low intelligence, and lack of forethought—failed to implement an emergency evacuation plan.
How to type an Em dash on a computer
On a Windows PC, press Alt and type 0151 on the numeric keypad.
On a Mac, press Shift and Alt and – (hyphen) or press Command and M.
En dash ( – )
En dashes are used to indicate number ranges as well as connect elements of a compound adjective.
- Please read pages 255-319 in your lab manual.
- The Korean War lasted from 1950–1953.
- The patient was a three-year-old boy.
- Paul got a part-time job.
How to type an En dash on a computer:
On a Windows PC, press Alt and type 0150 on the numeric keypad.
On a Mac, press Alt and – (hyphen key).
Hyphen vs. dash
Hyphens are shorter in length than the em dash and en dash and are used to join words and separate syllables of a single word. A more detailed explanation, as well as examples, can be found on the hyphen page.