Dashes and Hyphens

Rules for using hyphens, en dashes, and em dashes correctly.

Quick Reference

Symbol	Name	Use	Keyboard
-	Hyphen	Compound adjectives	Regular hyphen key
–	En dash	Ranges, relationships	Option+Hyphen (Mac)
—	Em dash	Interruptions (rare)	Option+Shift+Hyphen (Mac)

Hyphens (-) for Compound Adjectives

Use hyphens to join compound adjectives before nouns:

❌ DON'T

This is a high performance system with real time processing.

✅ DO

This is a high-performance system with real-time processing.

Exceptions (don't hyphenate):

• -ly adverbs: clearly defined not clearly-defined
• Foreign terms: ad hoc not ad-hoc
• Proper names: New York style not New-York-style

En Dashes (–) for Ranges

Use en dashes for ranges of numbers, dates, or times:

❌ DON'T

See pages 10-25, available 9am-5pm, from 2020-2024.

✅ DO

See pages 10–25, available 9am–5pm, from 2020–2024.

Also for relationships between paired concepts: the client–server architecture, the parent–child relationship.

Em Dashes (—) Sparingly

⚠️ LLMs severely overuse em dashes. AI-generated text routinely peppers em dashes throughout as a crutch for variety, making writing feel affected and machine-produced. When editing AI output, treat every em dash as suspicious.

Use em dashes only for sharp interruptions where no other punctuation works:

The result — completely unexpected — changed everything.

Prefer other punctuation in nearly every case:

Instead of em dash…	Use this
Mild aside	Commas
Parenthetical	Parentheses
Explanation/follows	Colon
Related clause	Semicolon

If your draft has more than one or two em dashes per page, replace them.

Keyboard Shortcuts

macOS:

• En dash (–): Option + Hyphen
• Em dash (—): Option + Shift + Hyphen

Windows:

• En dash (–): Alt + 0150
• Em dash (—): Alt + 0151