Dashes come in different sizes: hyphen, en dash, and em dash. They each have different functions. Worse yet, the different official writing styles (AP vs. Chicago) have different rules.
En dash (–, a dash the width of the proportional letter “n”)
–Whichever type of keyboard you use, no “en dash” key exists. The AP Stylebook uses spaces before and after the en dash (15 – 20). The Chicago Style uses only the en dash with no spaces (15–20). MS Word will let you create either one.
If you type on a Mac, press “Option” and the hyphen at the same time.
Windows does not make it so easy. Click on the “Insert” tab. To the far right, click on “Symbol” and at the bottom of the list, “More Symbols.” Under the “Special Characters” tab, select the second item in the list, “En Dash,” click “Insert,” and “Close.”
Or you can create a shortcut key from the “Special Characters” tab. At the bottom of the box, click on “Shortcut Key…” With the cursor in “Press new shortcut key:” in the middle of the box, press “ctrl” and “shift” and “N.” In the lower left, click on “Assign.” Close. Now whenever you need an en dash, hold “ctrl” and “shift” and type “N.” The dash will appear appropriately without spaces on either side.
“Official” uses for the en dash
A range of related numbers or a span of time:
- Thomas Edison (1847–1931) is best known for creating the electric light bulb.
- The longest assignment she gave was to read pages 45–91.
- Franklin D. Roosevelt served the longest time as President of the United States, 1933–1945.
- The class meets each week, Tuesday–Thursday, 8:00 a.m.–9:30 a.m.
- The score was close in the high school basketball game, 75–74, with the home team losing just before the Homecoming Dance.
- The longest assignment she gave was to read from page 45 to page 91.
- Franklin D. Roosevelt served the longest time as President of the United States, between 1933 and 1945.
Prefix to a proper noun:
However, common usage prefers the hyphen.
- pre–Revolutionary War pre-Revolutionary War
- post–Depression Era post-Depression Era
- pre-Revolutionary War pre-Revolutionary War
- post-Depression Era post-Depression Era