Overview
A hyphen (-) joins compound words and modifiers (well-known, twenty-five, self-employed). An em dash (—) creates emphasis, sets off extra information, or marks an abrupt change. An en dash (–) shows ranges (pages 10–20). Each has a distinct role in written English.
Hyphen (-)
- Compound adja well-known author · a five-year plan
- Compound nounmother-in-law · co-worker · self-esteem
- Prefixpre-existing · re-examine · ex-partner
- Numberstwenty-one · sixty-three
En Dash (–) and Em Dash (—)
- En (–)Ranges: pages 10–20 · the 2019–2022 period · London–Edinburgh
- Em (—)Parenthetical: The decision—unexpected by all—was announced Monday.
- Em (—)Interruption: 'I can't believe—' she began.
- StyleAmE: em dash with no spaces. BrE: often spaced en dash.
Common Mistakes
- ❌ a well known author → ✅ a well-known author (predicate: 'the author is well known' = no hyphen)
- ❌ Using hyphen (-) for ranges → ✅ use en dash (–): 2020–2022
- ❌ co operate → ✅ co-operate or cooperate
When to use
Compound adjectives
She delivered a thought-provoking, well-researched presentation.
Date ranges
The contract covers the 2023–2026 fiscal period.
Em dash emphasis
The result—surprising to everyone—was a unanimous vote.
Compound nouns
Her mother-in-law is the company's chief executive.