40 spelling is a little weird.
Why is there a U in four and fourteen, but not in forty?
Spelling the number 40 is one of the oddities of the English language.
So what’s the story with how to spell forty and is the word fourty still in use?
The history of the word forty
You might think that the difference in spelling is an American and British English variation such as in color and colour.
But the correct spelling is forty in both.
According to the Oxford English Dictionary, the word derives from the Old English words féowertig and féowurtig. These were in use between the 7th and 11th centuries.
Later in Middle English during the 12th and 15th centuries, it changed to fowwerrtig and feortig.
There were other variations including feouwerti, fuerti, feowrti, fourte, fourti, vourti, vourty and fourty.
One of the earliest uses of fourty appears in Chaucer’s Canon’s Yeoman’s Tale in 1386. If that thee list it have, Ye shul paye fourty pound.
The word fourty appeared in the latter part of this time and stayed in use between the 15th and 18th centuries.
Merriam-Webster believes that it wasn’t until the 18th century that the word forty came into popular use.
However, it is unclear as to why the U disappeared at this time. No one seems to know.
On a personal note, my favorite number is 42.
I wonder if Douglas Adams gave thought about how to spell 42 when he wrote The Hitchhiker’s Guide to the Galaxy. He probably did, I’m sure.
Spelling 40 is a common mistake
For anyone learning English, the correct spelling of 40 is a surprise. Four, fourteen, forty!
Even more, when you think for a fraction it is one-fourth because it relates to four.
But for an ordinal number, it is the fortieth because it refers to forty.
All you can do is accept that there is no U in forty, and that’s the rule.
It’s not much different to five and fifty. It’s simply about spelling and ease of pronunciation.
Do writers still use fourty?
It’s not unusual to still find the word fourty occasionally in modern writing.
Nature World News published an article in 2016, and the following quote is still appearing.
Female grey whales are fighting for their life. Fourty-three female whales are breeding in the group in 2015, a big increase from the 27 female whales in 2004.
If you’re interested in astronomy and physics, you might want to read, Fourty Years of Solar Spectroscopy. It was published in 1965 and is still listed on Semantic Scholar.
The National Library of Medicine lists an article titled, One hundred fourty years after the discovery of islets by Paul Langerhans.
It’s hard to know if these uses of the word fourty are intentional or a mistake.
It could just be that there are a few writers who think that the word looks more profound or scholarly with a U.
It pays to check your 40 spelling
I doubt that any writer would have a problem with how to spell 40.
But perhaps be careful when you write it as a fraction or as an ordinal number.
Yes, we all have terrific spell checkers now and rarely consult a dictionary. However, never place your entire trust in online checking tools.
It’s more fun to investigate our language and try to remember some of its little oddities.