Punctuation: Learn It 3

Dashes

There are two types of dashes—em dashes and en dashes.

The Em-dash

The dash functions (like a colon) to add emphasis to the preceding material.  In effect, a dash allows you to redefine what was just written, making it more explicit. You can also use a pair of dashes in place of parentheses, to frame an interruptive or parenthetical-type comment that you do not want to de-emphasize.

  • Appropriate alternative text for this image can be found in the caption.
    Figure 2 . An em dash.

    Jill Emery confirms that Muslim populations have typically been ruled by non-Muslims—specifically Americans, Russians, Israelis, and the French. (The em dash here gives extra emphasis to the examples of non-Muslims (American, Russians, Israelis, and the French).

  • The dissolution took 20 minutes—much longer than anticipated—but measurements were begun as soon as the process was completed. (The pair of em dashes here work like parentheses to add emphasis to the fact that 20 minutes was much longer than anticipated.
There is no “dash” button on a computer keyboard. Instead, create it by typing the hyphen button twice in a row; or use the “symbol” option in your word processor; or use the Mac shortcut option + shift + —.

The En-dash

There is also an “en dash”—whose length is that of an N, between that of the hyphen and the em dash, and it’s best used with dates and numbers. It can also be used for flight or train routes.

  • Appropriate alternative text for this image can be found in the caption.
    Figure 3. An en dash.

    July 6–September 17

    • The date range began on July 6 and ended on September 17.
  • Barack Obama (1961–)
    • This indicates the year the former president was born as well as the fact he is still alive.
  • pp. 148–56
    • This indicates pages 148 through 156. With number ranges, you can remove the first digit of the second number if it’s the same as the first number’s.
  • The London–Paris train will be running thirty minutes late today.
    • This indicates that the departing location is London and the destination location is Paris.
Like the em dash, the en dash is not on the standard computer keyboard.  Select it from word processor’s symbol map (or if you have a Mac, you can type option + –), or it may even be inserted automatically by your word processor when you type inclusive numbers or dates with a hyphen between them. In most contexts, a hyphen can serve as an en dash, but in professional publications—especially in the humanities—an en dash is correct.

When you type the hyphen, en dash, and em dash, no spaces should appear on either side of the punctuation mark.