Ever typed a little dash and wondered whether it was the "right" one? You are far from alone. The hyphen, en dash, and em dash look almost identical, yet each does a different job, and mixing them up is one of the most common punctuation slips in academic writing. So let's untangle all three, in plain language.
Here is the short version first. A hyphen joins words, an en dash shows a range or a relationship, and an em dash sets off a phrase for emphasis. They also differ in length: the hyphen is shortest, the em dash is longest, and the en dash sits in between. Most authors use them interchangeably, but reviewers and editors notice the difference at once, so this guide explains what each mark does, how to type it, and which rules apply in APA, MLA, and Chicago style.
The three marks at a glance
Before the detail, here is the whole picture in one table. Keep it handy as you read.
| Mark | Looks like | Main job | Example |
|---|---|---|---|
| Hyphen | - | Joins words | well-known author |
| En dash | – | Shows a range or link | pages 10–20 |
| Em dash | — | Sets off a phrase | The result—surprising—held up. |
A simple memory aid helps here. The en dash is about the width of a capital "N," and the em dash is about the width of a capital "M." The hyphen is shorter than both. If you ever want to double-check one, Merriam-Webster's guide to the three marks is a handy reference.
The hyphen: joining words
The hyphen is the shortest mark, and its main job is to join words or parts of words. It is also the one you already know best.
Use a hyphen for compound modifiers before a noun, such as a well-known researcher, a high-quality study, or a two-year trial. Use it for certain prefixes too, though many no longer need one; in academic style, "nonsignificant" is usually preferred over "non-significant," so check your style guide.
One quick rule prevents most errors. A hyphen never takes spaces around it, so write "state-of-the-art," not "state - of - the - art."
The en dash: ranges and relationships
The en dash is the middle mark, and it is the one most authors forget even exists. It has two main uses, and both are easy to learn.
First, it shows a range, replacing the word "to." For example: pages 45–58, the years 2010–2020, or 9 a.m.–5 p.m. Second, it shows a connection or relationship between two equal things, such as the author–date system, the dose–response curve, or the north–south divide.
There is also one more advanced use worth knowing. When one part of a compound already contains a space, an en dash joins the whole thing more clearly, as in a post–World War II policy, or a New York–based company. To type an en dash, use Ctrl+Minus on Windows or Option+Hyphen on a Mac.
The em dash: emphasis and interruption
The em dash is the longest mark, and the most dramatic; it sets off information for emphasis and can replace commas, parentheses, or a colon.
Use one em dash to add a phrase at the end of a sentence, as in: The findings supported one conclusion—early intervention works. Use a pair of em dashes to insert a phrase in the middle, as in: The results—both published and unpublished—pointed the same way.
Handle it with care, though. Many academic style guides, including APA, recommend using the em dash sparingly. So if you find yourself using several on one page, ask whether commas or parentheses would read better. To type an em dash, use Alt+0151 on Windows or Option+Shift+Hyphen on a Mac.
Spacing: the rule that trips people up
Spacing around the em dash causes constant confusion, but fortunately the academic rule is simple. In APA, MLA, and Chicago style, the em dash takes no spaces on either side. So write "word—word," not "word — word."
British English sometimes differs here. It often uses a spaced en dash ( – ) in place of the em dash, so if you write in British English, check your target journal's preference.
En dashes and hyphens also take no surrounding spaces in these styles. The one common exception is a spaced en dash used as a minus sign.
How the styles differ
The core idea is the same across styles, but the details vary, so always confirm what your target journal or institution requires.
- APA uses all three marks, places no spaces around dashes, and advises limiting the em dash.
- MLA uses all three, with no spaces around the em dash.
- Chicago uses all three and has detailed rules for en dash use in compounds.
- AP style, common in journalism, does not use the en dash at all and puts spaces around the em dash.
This is exactly the kind of rule the APA Style guidance on hyphens and dashes spells out in detail. If your work uses a specific citation style, our APA 7th edition checklist and our APA vs MLA vs Chicago guide explain the wider formatting rules.
Don't confuse the minus sign
One more mark deserves a mention, because it is easy to mix up. The minus sign is not a hyphen, and it is not a dash.
A true minus sign is about the length of an en dash but sits slightly higher. In most academic styles, you use a spaced version for equations, such as "a − b." For a negative value, use a space before but not after, as in "−5.25." Where a real minus sign is unavailable, a hyphen is the common fallback.
Common dash mistakes
Scan this list before you submit, since each one is common and easy to miss.
- Using a hyphen for a range, such as "pages 10-20" instead of "pages 10–20".
- Adding spaces around an em dash in APA, MLA, or Chicago style.
- Overusing the em dash, which weakens its effect.
- Ignoring the en dash entirely and using a hyphen everywhere.
- Mixing styles within one document.
- Using a hyphen as a minus sign in equations.
These are small marks, but consistency signals care. Our guide on colon vs semicolon covers another pair of punctuation marks that authors often confuse.
Your quick dash checklist
Check these six points before you submit:
- Ranges use an en dash, not a hyphen.
- Relationships between equal terms use an en dash.
- Compound modifiers before a noun use a hyphen.
- Em dashes set off phrases and are used sparingly.
- No spaces surround dashes in APA, MLA, or Chicago style.
- The same style is applied consistently throughout.
Frequently asked questions
What is the difference between an en dash and an em dash? An en dash (–) is shorter and shows a range or a relationship, such as "pages 10–20" or "the dose–response curve." An em dash (—) is longer and sets off a phrase for emphasis, often replacing commas or parentheses. The em dash is about the width of a capital "M," the en dash the width of a capital "N."
When should I use an em dash? Use an em dash to set off information for emphasis or to interrupt a sentence, either singly at the end or as a pair in the middle. In academic writing, use it sparingly, and consider commas or parentheses where you are using several on one page.
When do I use an en dash instead of a hyphen? Use an en dash for ranges, such as "2010–2020," and for connections between two equal terms, such as "the author–date system." Use a hyphen to join words into a single compound, such as "well-known." A hyphen joins; an en dash links or shows a span.
Do em dashes have spaces around them? In APA, MLA, and Chicago style, no. Write "word—word" with no spaces. British English sometimes uses a spaced en dash instead, so check your target journal's style if you write in British English.
How do I type an em dash and an en dash? For an em dash, press Alt+0151 on Windows or Option+Shift+Hyphen on a Mac. For an en dash, press Ctrl+Minus on Windows or Option+Hyphen on a Mac. Many word processors also convert two hyphens into a dash automatically.
Is a hyphen the same as a minus sign? No. A minus sign is about the length of an en dash and sits slightly higher. Academic styles use a spaced version in equations, such as "a − b," though a hyphen is a common fallback when a true minus sign is unavailable.
Conclusion
Hyphens and dashes are small, but they carry real meaning. Use a hyphen to join words, an en dash for ranges and relationships, and an em dash to set off a phrase, sparingly and without spaces.
Above all, apply one style consistently. When your punctuation is precise, reviewers focus on your research rather than your dashes, even on your very first paper.
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