Real-time suggestions, wherever you write.

Get GrammarlyIt's Free

Real-time suggestions, wherever you write.

Get GrammarlyIt's Free

Hyphen In Compound Adjective With Numbers

When numbers are used as the first part of a compound adjective, use a hyphen to connect them to the noun that follows them. This way, the reader knows that both words function like a unit to modify another noun. This applies whether the number is written in words or in digits.

Here’s a tip: Want to make sure your writing always looks great? Grammarly can save you from misspellings, grammatical and punctuation mistakes, and other writing issues on all your favorite websites.

The president of the company gave a 10-minute speech to the Board of Directors.
He is knowledgeable in thirteenth-century politics.
The boy threw a rock at the second-story window.

In some compounds with numbers—namely, with the number at the end of the compound—a hyphen is also not required. Take a look at the examples below, where the compound clearly functions as one standalone unit: 

He is a victim of Type 2 diabetes.
We’re not allowed access to the Basement 3 storage facility.

Hyphen in Compound Adjective With Fractions

When using a fraction (e.g. half or quarter) as part of a compound adjective, it should be hyphenated so the reader understands which fraction is modifying which noun.

I half-wanted to commit a felony.
A quarter-million dollars is still a large amount of money.
You’ll need one-third of a pound of flour and one egg.
That’s a half-baked idea if I ever heard one!

Hyphen With Number of Years

Use hyphens when you are using someone’s age as a label.

Four-and-a-half-year-olds are not reasonable about nap time.
The two-year-old’s favorite food was yogurt.

Don’t use hyphens when you’re just talking about a span of time.

We’ve lived here for four and a half years.
Two and a half years is plenty of time to learn how to play tennis.

Your writing, at its best.
Get Grammarly for free
Works on all your favorite websites
Related Articles
Writing, grammar, and communication tips for your inbox.
You have been successfully subscribed to the Grammarly blog.

Write with confidence.

Get real-time suggestions wherever you write.
Get GrammarlyIt's Free
“Grammarly quickly and easily makes your writing better.”
— Forbes