Doing your dash: en rules and em rules …

Ever noticed how there are separate dashes of several lengths? Ever wondered how you use them correctly? Then, boy howdy, this is the blog post for you. (Yes, correct punctuation use excites me. I wrote a poem about semicolons once.)

En rules (also known as en dashes) are so called because they were traditionally the same length as an “n”. They can be typed in Word by pressing CTRL and the minus key on the number pad: –

(Note that “en” is pronounced like the letter, not like the French word for “in”.)

They can be used in a couple of ways. One is to connect spans of time or entities, with no spaces either side:

the January–February carnival

the US–Canadian border

The other way they can be used is to insert a break into a sentence, or to include a statement that could otherwise be broken out with commas or brackets/parentheses. If they are used for this they must have spaces either side.

My hair – which is really curly – refuses to do what it’s told.

Em rules (also known as, unsurprisingly, em dashes) are (also unsurprisingly) known as such because they are traditionally the same length as an “m”. They can be typed in Word by pressing CTRL, ALT and the minus key on the number pad: —

As with en rules, em rules can be used to insert a break or a parenthetical statement into a sentence. Unlike with en rules, though, they shouldn’t have spaces either side.

My hair—which is really curly—refuses to do what it’s told.

Em rules are also used to attribute quotations:

“Good books don’t give up all their secrets at once.” — Stephen King

Don’t use both “—” and “–” to break up your sentences in one document or you’ll look a little nutty. If you’re writing for a specific publisher, then you can have a look at other books they’ve published to see what they prefer. I personally use em rules in my writing, but at work the style is to use en rules.

Also, don’t overuse them. More than a set of en rules (or em rules) in a paragraph starts to make me feel like I’m being dashed in the eye!