This post is dedicated to my favorite punctuation mark—the em dash. Incidentally, an em dash is the punctuation mark that I typed just prior to its name in that last sentence and the one that I’m typing right here as well—that line separating one part of the text from another.
The em dash is also known as the long dash (as opposed to its relative, the en dash, or short dash, which has a very different function to be explained in a future post). An em dash can serve the same function as a comma, parenthesis, or colon, except that it adds an extra bit of emphasis to whatever follows it, or—in the case of a pair of em dashes—whatever text appears between them. In fact, that’s a good way of remembering how to use an em dash—the word emphasize begins with em, so use an em dash when you want a pause with some added emphasis.
For example, you can use an em dash like you would a comma to create a pause, as I did in the sentence above beginning with “Incidentally,” but it’s a slightly longer pause than a comma affords, placing more focus on the word or words that follow it. You can also use an em dash much as you would use a colon, to introduce something that explains or clarifies whatever precedes it, again, if you want to add that extra bit of emphasis to the word or words following it. I did this in the very first sentence of this post when I introduced my favorite punctation mark with the mark itself. Similarly, the sentence that I wrote above that contains two em dashes is an example of how a pair of them can act much like a pair of commas or parentheses would to set off the text between them. Em dashes are much more striking than commas or parentheses, so use them when you really want to draw the reader’s eye to the text that’s set apart. By contrast, if you’re adding a bit of text that isn’t as important (an afterthought, for instance), use parentheses instead.
Aside from the use cases mentioned above, there are a couple of additional instances when an em dash can be used that are specific to writing dialogue. You can use an em dash to indicate an interruption in a character’s speech, for example, “What the—?” Using an em dash in this way signals to the reader that the character’s sentence or thought was abruptly cut off. You can also break off part of a word in a character’s speech in this manner, such as, “What the f—?” Similarly to a pair of em dashes being used to insert a thought into a sentence, you can do the same when you’re interrupting a character’s dialogue with an action, without using speech tags like so-and-so said. An example of this is, “Hey”—she stepped between the man and her dog—”leave my dog alone!” Note that in instances like this, the dashes are not set inside in the quotation marks. I fully admit to writing constructions such as this one incorrectly; I always put the dashes inside the quotes.
Now that you know how to use an em dash, you might be wondering how to actually type one into your text. Well, unfortunately (in my opinion), the em dash isn’t exactly the easiest punctuation to type. If, like me, you work in a Mac OS, then you can typically just insert an em dash by typing two hyphens in succession on your keyboard (on a US keyboard, the hyphen key is located just to the right of the zero). I’ve found that this shortcut works in word processing programs, email, and when I’m typing on my iPhone. It doesn’t, however, work in WordPress, which means that if I want to use an em dash in a blog post like this one, I have to use this shortcut: Option+Shift+hyphen. In Windows applications, you can hold down the Alt key and the Shift key simultaneously along with the hyphen/minus key or hold down the Alt key, then press 0151 in sequence. Note that these shortcuts may not work on all types of computers or devices.
The correct way to format an em dash in your text is to place it right between the text with no spaces surrounding it. The only exception to this formatting is some writing that uses Associated Press (AP) publication style, such as news articles or magazines.
And that, gang, is all I’ve got on em dashes, except to say that, because they’re my favorite, you’ll obviously see a lot of them in my writing.