How to Use an Em Dash
Updated: Sep 20
Learn how to use the em dash so your punctuation packs a punch.
The Short Story
The em dash is used for two primary reasons:
To call attention to a part of the text
For sudden breaks or interruptions
You might be wondering what an em dash looks like. An em dash is this: “—.” It’s called an em dash because it’s the length of the letter “m.” It’s longer than an en dash (“–”) and much longer than a hyphen (“-”).
So, now that you know what it looks like, how do you use the em dash?
1. To call attention to a part of the text
The em dash stands out on the page more than other punctuation, so if you want to emphasize something in your sentence, use an em dash. An em dash can take the place of commas, parentheses, or colons.
Let’s look at some examples:
Replacing a Comma
Ex: She delicately traced the edges of the violin, an instrument that held many memories.
If you want the information that the violin held many memories to stand out, you can replace the comma with an em dash:
Ex: She delicately traced the edges of the violin—an instrument that held many memories.
Let’s compare two sentences. They have the same text, but one uses parentheses and the other uses em dashes.
Ex: The server (he had a short temper) threw the ketchup bottle against the wall.
Ex: The server—he had a short temper—threw the ketchup bottle against the wall.
The information “he had a short temper” stands out in both sentences, but with slight differences. With the parentheses, readers tend to consider the information to be a sidenote, sometimes skipping the content inside them completely. With em dashes, readers are more likely to pause and view the information as an emphasis to the sentence as a whole. The punctuation you ultimately decide to use will depend on how you want your readers to perceive the information offset by the punctuation marks.
Replacing a Colon
Ex: The idea was to create quite an interesting place: Count Dracula's castle.
If you want the interesting place to stand out a bit more, you can replace the colon with an em dash.
Ex: The idea was to create quite an interesting place—Count Dracula's castle.
2. To show interruptions
Another use for the em dash is to show interruptions in dialogue or thoughts.
Interruptions in Dialogue
Ex: Miles frowned. “I thought that the third act was—”
“Do we have to keep talking about the play? You’ve been droning on for ten minutes already,” Jane interrupted.
Here, the em dash shows that the sentence wasn’t finished, signifying that Jane cut off Miles before he could finish his sentence.
Interruptions in Thoughts
Ex: If only I had thought of the solution sooner, then we wouldn’t be in this miserable situation. When would the debt collector come? Would we keep the farm? Would I lose—crack!—What was that? Were the horses alright?
In this example, the character’s thoughts are interrupted by a loud sound that switches her gear of thinking from money problems to her horses.
CAUTION: A question mark and an exclamation point can come before an em dash, like in the previous example. But never put a comma, colon, semicolon, or period (unless it’s part of an abbreviation) before an em dash.
The Published Examples
“She didn’t want Wardley to see her cry, even though he had several times—like when Vittiore had a costume ball thrown in her honor, when Harris began teaching Vittiore in the evenings instead of Dinah, or when her father had forgotten to send her tea on All Tea’s Day.”
(Oakes, Colleen. Queen of Hearts. United Kingdom: HarperCollins, 2017, p. 57.)
In this example, an em dash is replacing a colon. Both punctuation marks would be correct, but the em dash stands out a bit more and lets the reader know that the following text are examples of times Wardley had seen Dinah cry.
“‘If you can’t find the brand of formula you typically buy for your baby, consider a store-brand formula from CVS, Walmart, Target, or any other reputable retailer—if any are still available,’ Dr. Sude suggests.”
(Macmillan, Carrie. “Baby Formula Shortage: 8 Tips for Parents.” Yale Medicine. News. Published May 19, 2022. https://www.yalemedicine.org/news/baby-formula-shortage.)
Here, the em dash is replacing a comma. The em dash packs a more powerful punch than a comma would in this instance. A comma would make the information that there might not be formula available blend into the sentence, but the em dash gives it more importance.
“San Diego Zoo Wildlife Alliance is saving and protecting wildlife—including plants—worldwide.”
(San Diego Zoo Wildlife Alliance. “Plants.” Plants. Accessed June 6, 2022. https://animals.sandiegozoo.org/plants.)
In this example, the em dashes are replacing parentheses. Some readers skip over parentheses altogether, so to make sure that readers know that San Diego Zoo includes plants in their wildlife, the writer used em dashes to make it stand out.