Dashes and hyphens
For such little lines, dashes and hyphens get a large amount of attention. Here's our guide.
Hyphens (-)
Compound modifiers
Use a hyphen in a compound modifier (two or more words that work together to function like one adjective) when the modifier comes before the word it’s modifying:
Study for one of our world-class degrees.
This long-term research project could change the world.
If the noun comes first, don't hyphenate:
Our degrees are world class.
This research project is long term and it could change the world.
The list is up to date and therefore usable.
Compound modifiers that include present or past participles follow the same rules as any other compound modifier. If it comes before the word it modifies, hyphenate it. When it comes after the word it modifies, don’t hyphenate it.
well-established principle
You don’t need a hyphen when your modifier is made up of an adverb and an adjective:
She was about to sit a notoriously difficult exam.
The lecturer was famous on campus for her wonderfully elegant explanations.
Compound nouns
Hyphenated compound nouns – unsurprisingly – have a hyphen between the words:
Over time, hyphenated compound nouns often become closed compounds (no hyphen and no space):
The freshers' fair is a great place to find out about all the extracurricular activities on offer.
Bring a notebook to your seminar.
Sometimes the words in compound nouns get abbreviated first, and then the hyphen disappears:
I receive too many e-mails.
If you're not sure whether a compound noun is hyphenated, closed, or open (with a space), check the Oxford English Dictionary.
Prefixes
Use a hyphen with prefixes ex-, self- and all-, and where it helps to avoid any confusion or mispronunciation:
The llamas were re-released earlier this year.
The event was attended by the UK's most pre-eminent young engineers.
And with prefixes before a proper name, number or date:
Hyphens and numbers
Numbers between twenty-one and ninety-nine are hyphenated when they’re spelled out:
When a number makes up the first part of a compound adjective, use a hyphen to connect them to the noun that follows them. This applies whether the number is written in words or in digits.
The 24-hour race started at midnight.
The race was 24 hours long and started at midnight.
Compass points
When compass points are used as directions use a hyphen (but not when the words are used to describe a geographic location):
We should head south-east.
I used to live in the south east.
Suspended hyphens
Don't use suspended hyphens – just hyphenate the adjective that comes directly before the noun:
full- and part-time study
For some compound words, versions with and without hyphens are considered equally valid. We use the following:
- childcare
- cooperation/cooperate
- coordinate
- interdisciplinary
- offer-holder
- postdoctoral
- postgraduate
- postholder
- wellbeing
En dashes (–)
Use a pair of en dashes – with a space either side – as parentheses instead of round brackets or commas:
The Hypsilophodon – a small dinosaur from the Early Cretaceous – was omnivorous.
Use a single en dash, with a space either side, to link two parts of a sentence instead of a colon or semi colon:
The bus was late today – we nearly missed the lecture.
Use an en dash, with no space either side, to link concepts or indicate a range of numbers:
The salary for the role is £20–35,000.
It's aimed at the 18–25 age bracket.
The German–Polish decision resolved the issue.
And between the names of joint authors, creators or performers to distinguish from the hyphenated names of a single person:
A Dwight–Taupin production.
Em dashes (—)
The only time we use an em dash is when referencing the source of a quote:
“Seven social sins: politics without principles, wealth without work, pleasure without conscience, knowledge without character, commerce without morality, science without humanity, and worship without sacrifice.” — Mahatma Gandhi