I didn’t learn the difference between the hyphen (-) and the dash (–) until I was working as a professional copyeditor. This was after four years of majoring in English as an undergrad, not to mention a masters degree! The distinction between these two punctuation marks is as much a visual thing as a grammatical thing. To wit, some people call the hyphen “the n-dash” (because it’s the length of the letter n) and the dash the “m-dash” (because it’s the length of the letter m).
To type a hyphen, press that line key between the 0 and the = ONE TIME: –
To type a dash, press that same button TWICE: —
Now you know the difference between how these two symbols look. Let’s move on to their meanings and usages.
The hyphen isn’t just shorter (remember, it’s the n-dash, as opposed to the m-dash); it does less in a sentence than a dash. It can hold up part of a word or phrase, like ex-husband or mid-1980s or sixty-seven or over-the-counter or X-ray.
If you’re not sure whether a word or set of words needs a hyphen, you have two options:
- Look it up in a dictionary
- Let the copyeditors at your company work it out
What a hyphen cannot do–because it is not strong enough–is hold up part of a sentence. For that, you’re gonna need a dash. See how I used a set of dashes to create a parenthetical statement in that previous sentence? I set off a phrase with dash on either end of it. If I had used a hyphen to do that, it would look like this-two hyphens trying to rope off a clause-and that would confuse my reader. Now that you know the difference between hyphens and dashes, see how the sentence I just wrote (the one directly before this one) looks like I’m creating brand-new compound words, this-two and clause-and, rather than neatly delineating one clause from another?
The nice thing about dashes, once you’ve distinguished them from hyphens, is that they can be quite all-purpose. You can experiment with them when a semicolon isn’t right, but you want something stronger than a comma. Notice when writers use dashes in their work. It’s a pretty forgiving piece of punctuation, and one I think you’ll find quite useful in your own writing.