When it comes to the number 40, many people face confusion about whether it should be spelled forty or fourty. From my experience teaching English and exploring its history, I’ve noticed this question pops up frequently in both writing and everyday communication. The rules of spelling have evolved over centuries, influenced by Middle and Old English, and while the etymology of forty makes it clear, the mistaken fourth still appears in modern usage. Understanding the numeric digits, words, and their meaning can help remove any doubt when you write or read.
In practical terms, maintaining clarity and consistency is key. Using the correct pronunciation and spelling of forty aligns with modern standards of English grammar, vocabulary, and writing. Whether you’re teaching, learning, or working with numerals in an article or education material, knowing the origin and linguistic patterns ensures your context, reading, and communication are accurate. Even small details like the total count of digits or numeric representation can impact clarity, making it easier to explain and use the number correctly
The Correct Spelling: Forty
The word “forty” is the only correct spelling in modern English. There is no accepted alternative in standard usage, and any other variation is considered a misspelling.
Historically, English has evolved in strange ways. The word “forty” comes from Old English “fēowertig”, which combines “fēower” (four) and “-tig” (a group of ten). Over time, English simplified spellings, and the “u” from four was dropped, leading to the modern spelling “forty.”
This spelling is standard across both American and British English, which means whether you’re writing for a US audience or a UK audience, “forty” is always correct.
Here are some examples of correct usage:
- I have forty apples in my basket.
- She celebrated her fortieth birthday yesterday.
- The team scored forty points in the game.
Notice how the word integrates smoothly into sentences without any spelling issues.
The Common Mistake: Fourty
Many people incorrectly write “fourty” because it looks logical—it’s derived from the number four. Our brains naturally want to include the “u,” since four has it. This is a common phonetic mistake.
- However, “fourty” is never correct in any formal or informal English reference. Dictionaries like Merriam-Webster and Oxford English Dictionary clearly list forty as the only proper spelling.Incorrect: She turned fourty last year.
- Correct: She turned forty last year.
Understanding why this mistake occurs helps in remembering the correct spelling.
Origins and Etymology
The origin of forty traces back to Old English, where it was written as fēowertig. In this language system, numbers were often written as a combination of the base number and a suffix for multiples of ten
- fēower = four
- tig = a group of ten
So, fēowertig literally meant four tens. Over centuries, English simplified many words, removing unnecessary letters for efficiency, which is why the “u” in forty disappeared.
Interestingly, this is unique because most other multiples of ten, like thirty, fifty, sixty, do not drop letters in the same way. This historical quirk is why forty looks unusual compared to four, even though the two are closely connected.
Tips to Remember the Difference
Even native speakers often hesitate when writing forty. Here are some practical tips to avoid mistakes:
- Mnemonic trick: “Four has a ‘u,’ but forty does not.”
- Think in decdes: Remember the 1940s or 1980s—these are always spelled forties, never fourties.
- Visual cue: The word forty has exactly five letters, which is easier to remember visually.
- Practice writing: Write out numbers in words whenever you can to reinforce memory.
Using these methods, you can reduce errors in essays, emails, and social media posts.
Common Usage Examples
Let’s look at correct and incorrect usage in a table format for quick reference:
| Number | Correct Spelling | Incorrect Spelling |
| 40 | Forty | Fourty |
| 41 | Forty-one | Fourty-one |
| 42 | Forty-two | Fourty-two |
| 45 | Forty-five | Fourty-five |
| 49 | Forty-nine | Fourty-nine |
Example sentences using correct spelling:
- The marathon runner completed forty-two kilometers.
- I visited forty-one countries last year.
- The library has forty-five rare books.
These examples show how forty is widely used in real-life contexts.
Fun Facts About Forty
The number forty has significance beyond spelling. It appears frequently in culture, religion, science, and lierature:
- Idioms:
- Life begins at forty – popular saying about midlife.
- Over the hill at forty – used humorously to refer to aging.
- Historical references:
- Forty days and forty nights – famous biblical reference.
- Scientific significance:
- Forty is the atomic number of zirconium in chemistry.
- Cultural references:
- Popular movies, books, and songs mention forty in titles and lyrics.
Knowing these associations makes forty more memorable in your writing.
Case Studies: Common Mistakes Online
Many blogs, social media posts, and even professional publications occasionally use “fourty.” Here are a few real-life scenarios:
- Social Media Posts: Influencers often write “I can’t believe I’m fourty!” – wrong spelling.
- Student Essys: Students writing “The company turned fourty years old” lose marks for spelling errors.
- Professional Emails: Using fourty in a report or presentation can appear careless.
These examples highlight why proper spelling is essential for credibility.
Why Forty is Tricky
People struggle with forty for a few reasons:
- It doesn’t match the spelling of four, creating cognitive dissonance.
- Many spellcheckers may not flag fourty in informal writing, so mistakes go unnoticed.
- The human brain prefers phonetic logic, which leads people to insert the “u.”
Understanding this makes it easier to accept the irregularity and remember the correct form.
Tips for Writing Numbers in Words
Spelling numbers correctly is not just about forty. Here are general rules that help:
- Numbers 1–20: Unique spellings (one, two, three… twenty).
- Tens: thirty, forty, fifty, sixty…
- Hyphenate 21–99 when written in words: forty-one, fifty-two.
- Large numbers: Use commas for clarity (one thousand, ten thousand).
Following these rules ensures that your writing is professional and error-free.
Conclusion
Understanding the correct spelling of forty is simpler once you know its history, origin, and etymology. While fourty is a common mistake, following the rules of English, grammar, and writing ensures your communication, reading, and use of numerals remain clear and professional. Paying attention to numeric digits, pronunciation, and patterns across centuries helps avoid confusion and maintains consistency in both education and everyday usage.
FAQs
Q1: Is it ever correct to write “fourty”?
No. The correct spelling is always forty. Fourty is considered a misspelling in English.
Q2: Why do people confuse forty and fourty?
The confusion comes from historical influence of Middle and Old English and the irregularities in linguistic patterns over centuries.
Q3: How can I remember the correct spelling?
Think of the numeric digits 4-0 and pair them with the word forty. Keeping clarity and consistency in writing helps reinforce it.
Q4: Does the pronunciation differ between “forty” and “fourty”?
No, the pronunciation is the same. Only the spelling differs, with forty being the correct English usage.
Q5: Does this affect teaching or education?
Yes. Correct spelling, grammar, and vocabulary are important in teaching, learning, and all forms of communication involving numbers.
Lily Grace 
Ruby Skye