Now that we’ve talked about hyphens, let’s take a look at similar-looking but totally unique dashes—and there are two of them.
The em dash (—) is the length of three hyphens and is not to be confused with the en dash (–), which is the length of two hyphens. Though they are similar they both have distinct purposes, and I see people confuse them all the time.
En dash (–)
The en dash is the less common dash, but it is still important to know how to use one properly, especially if you type numbers with any regularity. An en dash is the width of the letter N which is how they get their name.
The main use for an en dash is to indicate number ranges.
The 2017–2018 school year was an important one for Meg.
The cost of redoing the bathroom will be $5,000–$6,000.
The store is open from 10:00 a.m.–3:00 p.m.
En dashes are also used in compound words when the base words are already hyphenated or when two word phrases are used as base words.
The Golden Globe–winning actor gave a speech.
The pro-pineapple–anti-pineapple argument lasted long after the pizza arrived.
Em dash (—)
The em dash is probably what comes to mind when you think of dashes. It is arguably the most versatile type of punctuation in the writer’s tool chest, standing in for commas, parentheses, or even semicolons, as well as serving its own unique purposes. Its name comes from the fact that an em dash is the same width as a letter M. En dashes are primarily used to separate ideas in a sentence, but there are many ways to achieve that.
Appositives that contain commas
An appositive is a piece of extra information included in a sentence. Normally, these are delineated from the main sentence with commas like this:
I ran into Mrs. McKinney, my fourth grade math teacher, at the store.
The words inside the commas give us more information on Mrs. McKinney. When the extra information you want to convey contains commas, you can use em dashes to set apart the extra information and avoid any confusion that comes with too many commas.
Joe made his usual breakfast—eggs, bacon, toast, and plenty of coffee—before he went to get the paper.
Sara stared at the hole in the window—the new, just-replaced-last-week window—in horror.
It should also be noted that if you have a sentence with too many commas, you can always separate out one of the phrase with em dashes.
Mark an abrupt change in thought
Another common use for em dashes is to show a sharp shift in thought. This is especially common in dialogue.
“Are you even listening to—oh, never mind.”
“Are you going to the—shoot, is that the time? I have to run.”
“How is the—No, get down from there!—project coming along?”
You can also use an em dash to show someone being interrupted.
“I was going to the—”
A bloodcurdling shriek shook the house.
Em dashes can also be used in place of parentheses to give further information or make comments in a way that is more connected to the text outside the dashes than it would be if you’d used parentheses. For example, if we compare:
I was working—or pretending I was—when my boss dropped by my desk.
I was working (or pretending I was) when my boss dropped by my desk.
These two sentences, while they have the same words and order, have a different feeling. Using em dashes makes the included information more connected with the rest of your sentence, while separating them off with parentheses is more closed off. It seems like offhand information.
When should you use em dashes and when should you use parentheses? You should chose em dashes if you want to emphasize the information contained in the aside. If you would say it out loud with stress on the aside, then dashes are the way to go. Otherwise, use parentheses. In the end, this is a stylistic choice, so it isn’t about right or wrong, but your style as a writer and what you want to convey in this case.
Instead of semicolons
A semicolon is used to connect two independent clauses; the em dash can also serve this purpose. If you choose to use an em dash instead of a semicolon, it will add more emphasis to your sentence, just as we have seen in previous examples.
Use an em dash when you want to stress the second part of your sentence—they really make your words stand out.
There are other uses for an em dash, but if you keep in mind that they can clear up comma clutter, add emphasis to an aside, and generally give separation to your writing, they will fit in seamlessly.
Using dashes in your writing
An important thing to note in all of these examples is that there aren’t any spaces before or after a dash. Ever. This is always true. Very often I’ll see authors type two hyphens and then a space or some similar combination in place of an em dash, and it just doesn’t work as well.
Since you don’t want to use hyphens—which are the only similar thing on the keyboard—how do you get an em dash? Honestly, figuring out how to type one in each different software can be a pain, but when in doubt, there is always copy and paste.
In Google Docs, you can insert an em or en dash by inserting a special character and then searching for an em dash, but this can be cumbersome. For ease of writing, I often put in three hyphens in place of the em dash and then do a find and replace all once I’m done with the draft.
With Word, you can insert em and en dashes through auto-formatting. If you type a word then two hyphens and then another word with no spaces, Word will automatically replace that with a em dash. You can do the same for an en dash with only one hyphen.
For other software or when writing on the web, it really depends. Sites like Tumblr and WordPress will often format three hyphens into an em dash and two into an en dash, so I recommend trying hyphens to see if it will auto-format for you, just for ease of use.
Keeping dashes in mind while writing allows you to have a greater deal of control over your writing—and of how your readers interpret it. Keep a few simple rules in mind, and your audience—and your editor—will be thanking you.