‘Fourty’ or ‘Forty’: How to Spell ‘40’ Correctly

By Shanea Patterson, updated on November 22, 2022

Need to spell out ‘40’ but not sure how to spell it? Is it ‘fourty’ or ‘forty’? We’ll go over that in more detail below. You’ll also learn a little bit about how to write out numbers and how to use them in a sentence in numerical and word form.

The short answer is that the correct way to spell the word is ‘forty’ not ‘fourty.’ Spelling it with a ‘u’ is incorrect.

How to Spell 40: Forty or Fourty?

You’ve already learned that ‘40’ is spelled out as ‘forty’ and not ‘fourty.’ But why?

‘Forty’ or ‘Fourty’? Which is Right?

You might be tempted to spell the word ‘fourty’ because of the way the word ‘four’ is spelled. But the English language is tricky when it comes to a lot of words.

In this particular case, you would drop the ‘u’ and spell it ‘forty.’ It doesn’t seem to make sense, but that’s actually the correct way to spell it.

How to Write Out Numbers 

Writing out numbers can be tricky for some people, especially since they don’t seem to follow the same rules between numbers one to twenty.

Here’s how you’d write out your numbers from one to twenty.

  • One
  • Two
  • Three
  • Four
  • Five
  • Six
  • Seven
  • Eight
  • Nine
  • Ten
  • Eleven
  • Twelve
  • Thirteen
  • Fourteen
  • Fifteen
  • Sixteen
  • Seventeen
  • Eighteen
  • Nineteen
  • Twenty

The rest of the numbers up to 100 generally repeat. Take a look:

  • Twenty-one
  • Thirty-two
  • Forty-three
  • Fifty-four
  • Sixty-five
  • Seventy-six
  • Eighty-seven
  • Ninety-eight

There would be no more new numbers introduced into the sequence after that. So, once you get these down, there are no new numbers to learn how to spell out.

Similar Confusing Words

Other confusing words similar to ‘forty’ are ‘ninety’ and ‘31st.’ 


Ninety is another word that can be confusing for some people to learn to spell. It simply means “a number equal to nine times 10.”


31st Some people struggle with whether to write ‘31th’ or ‘31st’ when writing out their ordinal numbers.

Definition and Meaning 

The Merriam Webster definition of the word ‘forty’ is: “a number equal to four times 10,” “forties: the numbers 40 to 49,” “the third point scored by a side in a game of tennis,” and “a forty-ounce bottle or another container of an alcoholic beverage (such as beer or malt liquor).”

A Brief History

The first known use of the word was before the 12th century, and it had the same meaning it does today.

It comes from the Middle English word fourty, the Old English word feowertig from feowertig, meaning a group of 40.

Phrases Containing the Word ‘Forty’

Take a look at some phrases that contain the word 'forty.'

  • Catch Forty Winks (sleep for a short time)
  • Forty Minutes of Hell (40 minutes of aggressive college basketball playing)
  • Forty Ways from Sunday (thoroughly and completely)
  • Forty-Something (a person in their 40s)
  • Life Begins at 40 (the belief that one will have the skills and experience to fully enjoy life)
  • A Fool at 40 is a Fool Forever (someone who reaches middle age and still acts immaturely)
  • Forty (malt liquor)

How to Use ‘Forty’ in a Sentence Correctly

Now that you know how to spell it let’s see how to use it in a sentence.

Take a look at a few examples:

  • I’m forty years old; how naïve do you think I am?
  • We have forty boxes coming into the warehouse tomorrow.
  • There are forty children, all screaming for the same balloon.

It’s also important to know that when writing in AP style, numbers from 0 to 10 should always be spelled out. Once you get past 10, they should be written in numerical form. However, when one number is below 10, and the other is above it, you’d use either one or the other (numbers or words). Never mix them.

One rule to follow is to use whichever comes first in the sequence. For example, if you have five and 100 and five comes first, you’d use word form (to follow the rule for fives). You’d do the opposite if 100 came first.

Concluding Thoughts on ‘Fourty’ and ‘Forty’

To recap, you’ve learned that ‘forty’ is the correct spelling of the number ‘40.’ Contrary to what you might’ve thought, there is no ‘u’ in forty. But there is a ‘u’ in ‘four.’

Don’t forget the difference. But if you ever do, you can always come back here and search through our library of articles dedicated to explaining confusing words and phrases.

We can also teach you how to write better and what certain English idioms and figures of speech mean.

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Written By:
Shanea Patterson
Shanea Patterson is a writer based in New York and loves writing for brands big and small. She has a master's degree in professional writing from New York University and a bachelor's degree in English from Mercy College.

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