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Fourty or Forty? How to Spell 40 Correctly…

This next installment of commonly misspelled words is a highly tricky one: How do you spell 40 as a word? Is it fourty or forty?

In related queries, is “40th” spelled fortieth or fourtieth? Do you write “40s” as forties or fourties? The correct answer to all these questions may infuriate you.

As background, my name is Lillie, and I’ve been an English teacher for nearly twenty years. I’m also an artist, so I hand-draw each and every educational illustration on this site — such as those on my article about how to decide whether to write flies or flys. Ready for the lesson? Let’s go!

Fourty or forty?
Fourty or forty? Here’s the answer!

Spell 40 Correctly

Let’s back up and start with the basics. First, we know that 4, the number between 3 (three) and 5 (five) is spelled: four, with an “ou” in the middle.

Second, we know that 14, the number between 13 (thirteen) and 15 (fifteen) is spelled: fourteen, also definitely with an “ou” after the “f.” Third, the number 400 (found between 399 and 401) is spelled “four hundred,” ALSO with an “ou.”

It all makes sense so far, right? Unfortunately, things are about to get weird as we enter the wild world of the number 40 — in which our entire spelling rhythm is thrown off.

Fourty or Forty?

Guess what? Even though four and fourteen and four hundred have an “ou” after the “f,’ when you spell 40 as a word, there is truly NO “u” anywhere in sight! That’s right — the correct way to spell the number that is four times ten is: FORTY.

How to spell 40
How to spell 40: It’s not totally logical.

“Fourty?” No!

Huh?! It — it may be illogical, but the word “fourty” (with a “u” in the middle) is simply a misspelling that doesn’t exist. It should be hurled out the window, never to be seen again — just like the common mistakes, “firey” (which got me almost as mad as “forty”), or “freind.”

To help you remember the spelling “forty” (vs. “fourty”), visualize the cartoon I’ve illustrated, above. In it, the forlorn number four is lamenting, “Why is my name, FOUR, not in FORTY?” The zero then responds, “FOR weird reasons.” (Note that this is different from how to spell 90, which DOES have the name of its first number, “nine,” in it.)

Is “Fourty” British? Also No!

Now here’s what’s even more confusing: As we we learned in our color or colour history lesson, there is a pattern that British English has “ou” for words where America has just “o,” such as “flavour” vs. “flavor.” In these cases, both are correct — they’re just used more predominantly in the corresponding region.

In the case of fourty vs. forty, however, this pattern does NOT hold true. The spelling “fourty” is wrong in BOTH regions, and no one should use it, no matter where they are. It’s not British, it’s just incorrect! Now, what about spelling variations on 40, like 40th or 40s?

Fourtieth vs. Fortieth, and Fourties vs. Forties

Like “fourty,” the spellings “fourtieth” and “fourties” don’t exist. They should be written as “fortieth” and “forties” — again, chucking the “u” far away. Those are also fake words like “recieved” or the confusingly popular “weither.”

Usage Examples:

Here are some common expressions using our friend 40 and its variations, written as words. Remember that every time you use a variation of “forty,” you need to leave out the “u.”

  • “Forty dollars,” NOT: “Fourty dollars.”
  • “Forty days and forty nights,” NOT: “Fourty days and fourty nights.”
  • “In the Forties,” or “He’s in his forties,” NOT: “In the Fourties,” or “He’s in his fourties.”
  • “Fortieth birthday party,” NOT: “Fourtieth birthday party.

Fourty or Forty, in Sum

Now you know: The correct way to spell 40 as a word is forty, not fourty. This belongs on our list of hard words to spell, because there is no “u” in fortieth, forties, or forty, even though there is one in four, fourteen, and four hundred. Ahh, English — never a dull moment!