Three horizontal marks, three different jobs. Mixing them up is one of the most common typographic slips, and one of the easiest to fix.
| Mark | Name | Unicode | Main job | Example |
|---|---|---|---|---|
| - | hyphen | U+002D | joins words and splits them at line ends | well-known, re-enter |
| – | en dash | U+2013 | ranges and connections | 2010–2015, pages 45–67, the London–Paris train |
| — | em dash | U+2014 | breaks in a sentence | The answer—if there is one—can wait. |
The hyphen
Hyphens join words that work together:
- Compound modifiers before a noun: a well-known author, a long-term plan. After the noun they usually drop the hyphen: the author is well known.
- Some prefixes: re-enter, co-owner, ex-partner, self-aware, and any prefix before a capital or number (pre-2020, anti-American).
- Numbers and fractions written as words: twenty-one, two-thirds.
Don’t hyphenate after adverbs ending in -ly: a highly regarded study, not highly-regarded.
The en dash
Named for the width of a letter n, the en dash means “to” or “and”:
- Ranges: 1990–1999, 9:00–5:00, pages 12–18, ages 5–7.
- Connections between equals: the Brexit–Covid economy, a Paris–Berlin flight, the Michelson–Morley experiment.
- Compound adjectives built on open compounds (Chicago): the post–World War II era.
Don’t combine an en dash with from or between: write from 2010 to 2015, not from 2010–2015.
In British and many European styles, a spaced en dash – like this – is also used as the sentence dash.
The em dash
The em dash sets off an interruption, an aside or a dramatic turn—more emphatically than commas, more casually than parentheses:
- Three people—Ana, Ben and Chloé—arrived early.
- She had one goal—to finish.
US style guides (Chicago, APA, MLA) use a closed em dash with no spaces. AP style, used by many US newspapers, puts spaces around it. UK publishers mostly prefer the spaced en dash instead. Pick one and stay consistent, the Consistency Checker flags mixtures.
Don’t overdo it: more than two em dashes in a paragraph usually means the sentence needs restructuring.
How to type them
| Windows | macOS | HTML | |
|---|---|---|---|
| en dash – | Alt + 0150 | Option + hyphen | – |
| em dash — | Alt + 0151 | Option + Shift + hyphen | — |
Most word processors also convert two hyphens between words into a dash. On the web, the Typography Fixer converts “--” to dashes and number ranges to en dashes in one pass, and Special Characters & Symbols lets you copy any dash with a click.
Common mistakes
- A hyphen used as a sentence dash (“word - word”). The Punctuation Checker flags it.
- Hyphens in ranges (“2010-2015”). Use an en dash, but leave dates like 2025-03-14 and phone numbers alone.
- Minus signs. In maths, use the true minus sign (−, U+2212), not a hyphen.
Sources
- The Chicago Manual of Style, 18th ed. (2024), chapter 6, “Punctuation”.
- The Associated Press Stylebook, “dashes” and “hyphen”.
- New Hart’s Rules (Oxford University Press), dashes.