Key takeaways:
- An em dash (—) is a punctuation mark used to add emphasis, set off extra information, or signal a break in thought.
- Writers use em dashes instead of commas, parentheses, or colons to create emphasis or make sentence structure clearer.
- Em dashes are especially useful for parenthetical information, appositives with commas, lists, and sharp turns in thought.
- Em dashes are different from en dashes (–), which are used for ranges, connections, or compound modifiers.
- If AI-generated text uses too many em dashes, you can prevent or remove them with clearer prompts or revision instructions.
Em dashes are one of the most flexible—and most misused—punctuation marks in English writing. They can replace commas, parentheses, or colons, add emphasis, and help guide readers through complex sentences without slowing them down.
That versatility is exactly why writers love em dashes, and why they sometimes get overused. Em dashes appear frequently in creative writing, journalism, and increasingly in AI-generated text, where they can signal emphasis or a shift in thought. Used well, they make writing clearer and more engaging. Used too often, they can distract or overwhelm.
In this guide, you’ll learn what an em dash is, when to use it, how it differs from an en dash, how to type one, and how to manage em dashes in AI-generated writing.
Table of contents
- What are em dashes?
- When to use an em dash
- Em dash vs. en dash
- How to type an em dash
- How to remove em dashes from ChatGPT
- Common mistakes to avoid with em dashes
- Em dash FAQs
What are em dashes?
Em dashes (—) are punctuation marks used to separate or emphasize parts of a sentence. They get their name from their length, which is roughly the width of a capital letter M.
Unlike commas or parentheses, em dashes create a stronger pause and draw attention to the information they surround. Writers often use them to add detail, clarify meaning, or signal a pause in thought.
Visually, em dashes are longer than hyphens (-) and en dashes (–), and they serve a different purpose than both.
In practice, em dashes often replace other punctuation marks such as commas, parentheses, colons, or even periods. Writers use them when they want to draw attention to a phrase, create emphasis, or signal a break in thought more strongly than a comma would.
Because em dashes are flexible and stylistic rather than rule-bound, their use often comes down to clarity and tone. When used intentionally, they can make sentences easier to follow and reduce clutter caused by excessive commas.
When to use an em dash
You should use an em dash when you want to emphasize information, reduce comma clutter, or clearly signal a shift or interruption in a sentence. When used carefully, em dashes can improve readability by clarifying relationships between ideas and reducing overreliance on commas.
Below are the most common and effective ways to use em dashes.
Use em dashes to set off parenthetical information
Em dashes are often used to insert extra information into a sentence. Compared with parentheses, em dashes keep the added information more prominent and connected to the main idea.
When using em dashes this way, use two em dashes (one before and one after the inserted material).
Example: While I was shopping—wandering aimlessly up and down the aisles, actually—I ran into our old neighbor.
Example: An etymological dictionary is one of the few books—no, it’s the only book—you’ll ever need.
Example: Traveling—that is, traveling by public transit—can be relaxing if you bring music and reading material.
Spacing around em dashes is a style choice, but consistency matters more than the choice itself.
Use an em dash to set off appositives that contain commas
An appositive is a phrase that adds extra information about a noun. Commas usually set off appositives, but when the appositive itself contains commas, additional commas can confuse readers.
In those cases, em dashes provide clarity.
Example: Four of us—Mike, Amanda, Katy, and I—went to the conference last week.
Example: Mr. M glanced at his watch—his gold, diamond-encrusted watch—and suggested the meeting might adjourn.
Example: The question words—who, what, when, where, why, and how—are used to retrieve information in English.
Use an em dash to bring focus to a list
When a sentence begins with a list and ends with an independent clause, an em dash can help link the ideas clearly and smoothly.
Example: Dishes, laundry, dusting—they’re all done now, and I need a rest.
Example: Chocolate, strawberry, vanilla—all ice cream tastes good, especially on a hot summer day.
Example: Do this, do that, go here, go there—there’s so much to do that I don’t get much accomplished.
Use an em dash to add emphasis
Writers often use em dashes to emphasize a word or phrase that deserves extra attention. Compared with commas or parentheses, em dashes make the emphasized content stand out more clearly.
Example: Winning that award—it changed her life.
Example: I thought the meeting would be routine—it wasn’t.
Example: There was only one problem—the deadline was tomorrow.
Used sparingly, this approach can highlight key moments or ideas without disrupting the sentence’s flow.
Use an em dash to mark sharp turns in thought
Em dashes are useful for signaling interruptions, sudden changes in thought, or dramatic emphasis. This usage is most common in informal or creative writing.
Example: Mary, could you—no, Mikey, don’t touch the knife!—Mary, could you please set the table?
Example: Dinner is at 6:30—not 6:29 or 6:31.
Example: Where is my—wait, what was I looking for?
Because this use can feel conversational, it’s best used sparingly in formal or academic writing.
Use an em dash to attribute quotes
Em dashes are sometimes used to attribute a quote to its speaker or author, especially in informal or creative writing. In this case, the em dash separates the quote from the attribution at the end of the sentence.
Example: “The only limit to our realization of tomorrow is our doubts of today.” —Franklin D. Roosevelt
Example: “Write what disturbs you, what you fear, what you have not been willing to speak about.” —Natalie Goldberg
Example: “The first draft of anything is terrible.” —Ernest Hemingway
This style is less common in formal academic writing, where attribution is usually handled with commas or parentheses.
Em dash vs. en dash
It’s easy to mix up em dash (—) and en dash (–), so here’s the difference:
- Em dash (—): Long; marks breaks in thought, emphasis, interruptions, or set-off parentheticals. Example: The project—once delayed—finally launched.
- En dash (–): Shorter; shows ranges and some compound relationships. Use it for number ranges (2019–2023), page spans (pp. 12–15), or to link open compounds (e.g., the New York–based firm).
A quick rule of thumb: Use an en dash for ranges or connections, and an em dash for breaks or emphasis.
How to type an em dash
An em dash (—) can be typed in several ways, depending on your device, operating system, and writing tool. Below are the most reliable methods across common platforms.
On desktop computers
- Mac: Press Option + Shift + hyphen.
- Windows: Press Alt + 0151 using the numeric keypad. This requires a keyboard with a numeric keypad.
- Microsoft Word: Type two hyphens (–) and Word will often convert them into an em dash automatically. In some versions, you can also use Ctrl + Alt + Minus on the numeric keypad.
- Google Docs: Go to Insert > Special characters, then search for em dash. If smart punctuation is enabled, typing two hyphens (–) may automatically convert to an em dash.
In code and markup
- HTML: Use — or —
- Markdown or plain text: If you can’t insert an em dash directly, you may see writers use — as a fallback, especially in plain text or markdown environments. When possible, it’s better to insert the actual em dash character to avoid formatting issues.
On mobile devices
- Press and hold the hyphen (-) key on the keyboard.
- Select the em dash (—) from the punctuation options.
How to remove em dashes from ChatGPT
Em dashes naturally draw attention in a sentence, which is why large language models (LLMs) often use them frequently in AI-generated text to add emphasis or signal shifts in thought. Because LLMs are trained on a wide range of writing styles, including journalism and explanatory prose where em dashes are common, text generated by AI may lean on em dashes more heavily than many human writers would.
Heavy use of the em dash can sometimes signal that the content was generated by an AI system like ChatGPT, especially when it appears repeatedly in short spans of text.
If you prefer a more restrained or traditional punctuation style, you can reduce or eliminate em dashes in ChatGPT or other AI-generated text with the right instructions.
Use a prompt to prevent em dashes in AI-generated text
If you want to avoid em dashes in a single response, include punctuation preferences directly in your prompt.
- Short prompt example: Please write this in a formal, neutral tone and avoid using em dashes. Use commas, periods, or parentheses instead.
- More specific prompt example: Draft a 300-word explanation of sprint planning. Use complete sentences, avoid em dashes entirely, and rely on commas or parentheses for asides.
Clear, specific instructions usually produce better results than a vague “don’t use em dashes” request.
If you want ChatGPT to avoid em dashes in all future responses, custom instructions are more effective than repeatedly issuing the same request. This is especially useful if you regularly edit or publish AI-generated content and want a consistent punctuation style.
In the “How would you like ChatGPT to respond?” field, you can add guidance like:
- In all responses, avoid em dashes and en dashes. Use periods, commas, or parentheses for sentence structure.
- Use standard punctuation only. Em dashes should not appear unless explicitly requested.
- Follow a no-dash writing style. Replace em dashes with commas or periods as appropriate.
This approach is more effective than negative commands alone because it clearly specifies what to do instead.
Use a prompt to remove em dashes from existing AI-generated text
If the text is already written, you can ask ChatGPT to revise it.
- Rewrite prompt example: Rewrite the following paragraph and remove all em dashes. Replace them with commas, colons, or parentheses so the tone stays natural: [paste text]
Quick manual fixes to remove em dashes
If you prefer to edit yourself:
- Use your document editor’s Find and Replace feature to locate the em dash character (—).
- Replace it with commas, parentheses, or periods depending on sentence structure.
Most word processors and text editors support this kind of targeted replacement.
When removing em dashes makes sense
Avoiding em dashes is often helpful when:
- Writing formal or academic content
- Aiming for a more traditional or conservative tone
- Revising AI-generated text to sound more human
- Following a specific style guide that discourages dash usage
In creative or narrative writing, em dashes can still be effective when used sparingly and intentionally.
Common mistakes to avoid with em dashes
Em dashes can improve flow and emphasis, but they need to be used carefully. Watch for these common issues.
1. Overusing em dashes
Too many em dashes in one sentence can make writing feel cluttered or overly dramatic.
- Overused: The report—while detailed—was late—and the data—although thorough—needed revision.
- Improved: The report was detailed but late, and the data, although thorough, needed revision.
If you find yourself using multiple em dashes in one sentence, consider simplifying or splitting it.
2. Using em dashes when another punctuation mark is clearer
Em dashes aren’t a replacement for commas, colons, or conjunctions.
- Unclear: She wanted to attend the meeting—it conflicted with her schedule.
- Clear: She wanted to attend the meeting, but it conflicted with her schedule.
Choose the punctuation that best explains the relationship between ideas.
3. Mixing em dashes with commas or other punctuation
An em dash should stand alone. Don’t pair it with a comma or colon at the same break.
- Incorrect: The team—after several delays,—finally shipped the update.
- Correct: The team—after several delays—finally shipped the update.
4. Forgetting the second em dash
When em dashes replace parentheses, they usually come in pairs.
- Incorrect: The deadline—originally set for Friday has been moved.
- Correct: The deadline—originally set for Friday—has been moved.
The exception is when the dash appears at the end of a sentence.
5. Inconsistent spacing around em dashes
Most modern style guides recommend no spaces around em dashes. Whichever style you choose, consistency is key.
- Inconsistent: The solution —although simple— took time to implement.
- Consistent: The solution—although simple—took time to implement.
6. Using em dashes in very formal writing
Em dashes can sound conversational, which may not suit academic or technical contexts.
- Less formal: The results—while interesting—require further study.
- More formal: The results, while interesting, require further study.
7. Using em dashes instead of revising the sentence
If a sentence relies on multiple em dashes, it often needs restructuring.
- Awkward: The policy—designed to improve efficiency—was confusing—leading to delays.
- Revised: The policy was designed to improve efficiency, but it caused confusion and delays.
When clarity suffers, rewriting is preferable to adding more punctuation.
Em dash FAQs
What is the purpose of an em dash?
An em dash (—) adds emphasis, clarifies meaning, or signals a pause or shift in thought. It often replaces commas, parentheses, or colons.
How do you use em dashes correctly?
Use em dashes sparingly to highlight important information, clarify appositives, or signal interruptions. Avoid overusing them or mixing dash styles inconsistently.
When should you avoid em dashes?
Avoid em dashes in highly formal or academic writing where clarity and restraint are prioritized. Overusing them can make writing feel unfocused.
Can you remove em dashes from ChatGPT?
Yes. You can prevent or remove em dashes by clearly instructing ChatGPT to avoid them or replace them with commas or parentheses.
What’s the difference between an em dash and an en dash?
An em dash emphasizes or separates ideas, whereas an en dash indicates ranges or connections, such as dates, times, or compound modifiers.
