You're standing there, pen hovering over a check or staring at a blank spot in a formal report, and suddenly your brain just glitches. It happens to everyone. You know the number is 40. You know the number 4 is spelled "four." So, naturally, your instinct screams that there should be a "u" in there. But when you type it out, it looks... off. If you've ever wondered how do you spell forty without looking like you skipped third grade, you aren't alone. In fact, it's one of the most common spelling errors in the English language, even for native speakers who write for a living.
The answer is short. It’s forty. No "u." Just F-O-R-T-Y.
It feels wrong, doesn't it? It feels like a betrayal of the English language's own logic. We have four, fourteen, and then—bam—the "u" just evaporates into thin air once we hit the fourth decade. This isn't just some weird modern slang or a regional Americanism. It’s a linguistic quirk that has survived centuries of change, and honestly, it’s one of the best examples of why English is such a headache to learn.
The Mystery of the Missing U
Why does this happen? To understand why how do you spell forty is such a frequent search query, we have to look at the history of the word. Etymology isn't always exciting, but here, it's the only thing that explains the madness. Middle English was a bit of a free-for-all. Back in the day, you might see it spelled fourty, fowrty, or even feowerti. There wasn't a standard "dictionary" way to do things.
Language evolves. Usually, it evolves toward simplicity, but sometimes it just moves toward whatever people happened to be doing in London a few hundred years ago. By the time the 1800s rolled around, "forty" had become the undisputed king of the hill. The "u" was dropped long before Noah Webster started his crusade to simplify American English. This means that unlike "color" vs "colour" or "flavor" vs "flavour," the spelling of forty is the same whether you are in London, New York, or Sydney.
It's one of the few things Americans and Brits actually agree on.
Comparing Forty to Its Cousins
If you're still doubting yourself, look at the family tree.
- Four: Has the "u."
- Fourteen: Has the "u."
- Fourth: Has the "u."
- Forty: No "u."
It’s an outlier. It’s the black sheep of the "four" family. Because "fourteen" keeps the "u," our brains naturally assume the pattern holds as the numbers get bigger. They don't. This is what psychologists and linguists sometimes call "overgeneralization." It’s the same reason a toddler might say "I goed to the store" instead of "I went." They learned a rule (add -ed for past tense) and applied it everywhere. As adults, we do the same thing with the "four" rule. We see the pattern, we trust the pattern, and then the English language trips us into the mud.
Does British English Use Fourty?
This is a massive misconception. Many people assume that if a word is missing a "u" in America, it must have one in the UK. We’re used to the British keeping those extra letters in words like honour or neighbour. But how do you spell forty in London? Exactly the same way you do in Los Angeles.
If you check the Oxford English Dictionary or any major British style guide—like the Guardian or the BBC—they all point to "forty." Using "fourty" in a British university essay will get you the same red ink as it would in a US classroom. It's a rare moment of transatlantic unity.
Why Do We Keep Getting It Wrong?
Honestly, it's mostly visual memory vs. logical reasoning. You see the word "four" thousands of times in your life. It becomes a foundation of your internal dictionary. When you go to expand that word into "forty," your hand wants to keep that foundation intact.
There's also the "forty-fourth" problem. Imagine writing that out. If you follow the rules, it's forty-fourth. One word has the "u," the other doesn't. When they are sitting right next to each other, the spelling of forty looks even more suspicious. It looks like a typo you made halfway through the sentence. But it's not.
Real-World Consequences of the Typo
Does it actually matter? In a text to your mom? Probably not. She knows what you mean. But in professional settings, it can be a subtle "tell."
- Check Writing: Banks are generally trained to look at the numerical value first, but if the written word is "fourty," it technically creates a discrepancy. While most tellers will process it anyway, why give them a reason to pause?
- Legal Documents: Contracts are built on precision. A misspelling in a major financial contract—like a forty-year lease—can occasionally cause unnecessary legal headaches if a lawyer wants to be particularly difficult about "intent."
- Academic Credibility: If you are writing a dissertation or a high-level thesis, misspelling a basic number is a quick way to lose the "expert" vibe you're trying to cultivate.
How to Remember It for Good
Since the logic fails us, we need a trick. Think about the word "fort." A fort is a strong, solid building. It doesn't have a "u" in it. Forty is a "strong" number—the age where people say life begins, or the number of days it rained in the biblical flood. If you can remember that a "fort" has no "u," you can remember that "forty" has no "u."
Another way? Think of the "u" as "U." You are not in forty. The letter U is just gone.
Other Number Spellings That Trip People Up
While you're fixing your spelling of forty, you might as well look at a few other culprits. English loves to make things difficult.
Take ninth. You take the word "nine," and you'd think you just add "th." Nope. You drop the "e." It’s N-I-N-T-H.
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Then there's eighth. It already ends in a "t," so you don't add another one. It’s just E-I-G-H-T-H.
And don't even get started on fiftieth. The "y" in fifty changes to an "i," and then you add "eth." Compared to those, forty is actually pretty simple. It just feels wrong because it breaks the "four" streak.
Actionable Steps for Flawless Spelling
If you want to stop Googling how do you spell forty every time you have to write a thank-you note or a business proposal, try these specific shifts:
- Update Your Autocorrect: Most modern browsers and phones will catch "fourty," but if yours doesn't, go into your keyboard settings and create a manual replacement rule. Tell it to always change "fourty" to "forty."
- The "Forty-Fort" Mental Image: Visualize a giant number 40 shaped like a stone fort. There’s no "u" in a fort.
- Read It Out Loud: Sometimes saying "for-ty" with a hard emphasis on the "o" helps you realize that the "u" sound (which you hear in "four") isn't really pulling its weight anyway.
- Double-Check the "Four" Family: Before you hit send on an important document, do a quick "Ctrl+F" for the "four" string. If you see "fourty," kill the "u" immediately.
The reality is that English is a living, breathing mess of old Germanic roots, French influences, and Latin leftovers. The spelling of forty is just one of those scars left over from history. It doesn't make sense, but it is the rule. Now that you know, you can write it with confidence. No "u," no problem.