Spell The Number 40 | Correct Spelling Rules

If you need to spell the number 40 for homework, an exam, or a report, the correct spelling is forty. Many learners write “fourty” because the digit form 4 links in the mind with the word four, yet English spelling in this case takes a different path.

This guide explains why forty looks this way, how to use it in sentences, and how to remember the pattern so you can spell the number 40 correctly every time.

Why English Spells 40 As Forty

The base word for the digit 4 is four, and related forms such as fourteen and fourth also keep the letter “u”. The tens form forty broke away from this pattern. Earlier English texts sometimes used “fourty”, but over time writers settled on forty as the regular form.

Modern dictionaries list only forty as the standard spelling, which means this is the form you should use in school work, exams, and any formal document. The same rule holds for its related forms, such as fortieth and phrases such as “the forties”.

Number	Word Form	Notes
4	four	Base number with “our” pattern
14	fourteen	Teen form still keeps the “our” letters
40	forty	Tens form drops the “u” and shifts to “or”
41	forty-one	Hyphen joins forty and the next digit word
44	forty-four	Both parts stay clear: “forty” then “four”
40th	fortieth	Ordinal form, add “ieth” to forty
40–49	the forties	Range of numbers or years from 40 to 49
1940s	the nineteen-forties	Decade name written with hyphen for clarity

The pattern in the table shows how four, fourteen, forty, and fortieth relate to each other. Four and fourteen keep the “our” letters, while forty and fortieth change to “or” and drop the letter “u”. The plural phrase “the forties” follows the same “or” line.

When spelling any of these forms, it helps to say them slowly out loud, paying attention to the sound /ˈfɔːr-ti/ for forty. That sound matches the spelling for-ty more closely than four-ty, which is one reason many teachers tell learners to picture the word “fort” when writing forty.

Spell The Number 40 In Everyday Writing

Many learners search for “Spell The Number 40” because they move between digits and words in different tasks. In some tasks you only need the digits 4 and 0, while in others you need the written word. The phrase spell the number 40 appears in school worksheets, spelling tests, and language exams in many countries.

The safest rule is simple: whenever you write forty or a related form as a word, drop the “u”. That rule holds in homework, essays, formal emails, and even creative writing. If you like to double-check, you can look up the Merriam-Webster usage note on forty, which points out that “fourty” is not a standard option.

When To Write Forty As A Word

Style guides differ a little on when to use digits and when to spell out a number. Many guides tell writers to spell out simple numbers from one to nine, and to use digits for 10 and above. Other guides ask writers to spell out any number that begins a sentence, including forty.

Here are some clear cases where writing forty as a word works well:

• At the start of a sentence: “Forty students entered the contest.”
• In formal prose where nearby numbers are also words: “The class has thirty desks and forty chairs.”
• In exam answers that ask you to “write the spelling in words”.
• In dictation tasks where the teacher reads out a sentence and you write each number as a word.

In maths work or data tables, digits often make reading easier, so “40 cm” or “40%” fits better. Even in those cases, the word form forty is still the one you should keep in your memory, because it guides other related spellings such as fortieth.

Hyphen Rules With Forty

Once you know how to spell forty on its own, the next step is learning how to join it with other numbers. When forty is followed by a one-digit number, English writing uses a hyphen.

Common examples include:

• forty-one
• forty-two
• forty-three
• forty-four
• forty-nine

Writers often forget the hyphen in quick notes, which leads to forms such as “forty one”. In a casual text message this may not cause confusion. In exams, school essays, or published work, “forty-one” with a hyphen looks far more polished and lines up with standard style guides.

Common Mistakes With Forty And Fourty

The most frequent slip is writing “fourty” by copying the letters from four. Spell-check tools in word processors usually catch this, yet learners still need a clear mental rule for times when no digital help is available.

Think of the word fort as in “a stone fort on a hill”. Add a “y” at the end and you get forty. The link between “fort” and the sound of forty works as a quick memory hook for many students.

Why “Fourty” Looks So Tempting

English number words do not always follow one pattern. We have pairs such as “two” and “twenty”, “three” and “thirty”, “five” and “fifteen”. In each pair the base number and the larger number show a link. Because of this, the brain expects “four” and “fourty” to line up in a similar way.

Historical spelling changes broke that link. Over a long period, printed books and teaching materials moved toward the simpler form forty. Modern reference works follow that line, and learner dictionaries such as the Oxford Learner’s Dictionaries entry for forty give only this spelling.

Other Tricky Forms Around Forty

Once you start working with forty in real sentences, a few other forms can cause trouble as well:

• fortieth – used for position: “She finished in fortieth place.”
• the forties – used for age: “He is in his forties.”
• the nineteen-forties – used for years: “The story is set in the nineteen-forties.”

Each of these keeps the “or” pattern. None of them use “fourty”. When you write dates or ages, it helps to pause for a second and check that the “u” has not slipped back into the word.

Context	Correct Form	Common Error
Simple number	forty	fourty
Ordinal position	fortieth	fourtieth
Age range	in his forties	in his fourties
Decade name	the nineteen-forties	the nineteen-fourties
Hyphen form	forty-five	fourty five
Exam answer	write “forty” in words	write “fourty” in words
Text message	forty or 40	fourty

Reading down the table a few times helps fix the forms in your memory. You see the same clear pattern in every row: the “or” vowel pair is always present in the correct spelling, while the version with “our” keeps turning up in the error column.

Teaching Children To Spell Forty

Parents and teachers often need simple steps to help younger learners master spellings like forty. Short, repeated practice works well here. The goal is to turn the spelling into a habit rather than a guess.

Step-By-Step Practice Ideas

You can build a small routine around the word forty and the phrase spell the number 40. A short daily routine might follow this pattern:

1. Say the word forty aloud together three times.
2. Write the word on a board while spelling each letter aloud: “f-o-r-t-y”.
3. Ask the child to copy the word twice on paper.
4. Cover the board and ask the child to write it again from memory.
5. Finish with one sentence that uses the word, such as “Forty birds sat on the tree.”

Repeating that routine on several days in a row gives the learner repeated contact with the correct form. The spoken spelling and the written shape begin to link together in the mind.

Short Games For Classroom Or Home

Games keep practice light while still building skill. Here are a few ideas that work well with forty and other number words:

• Number bingo: Create bingo cards with number words from ten to fifty. Call out “forty” and let learners mark it.
• Spelling race: Write “forty” and “fourty” on the board. Ask learners to run to the correct form and tap it.
• Matching cards: Make small cards with “40”, “forty”, and “fortieth”. Shuffle them and ask learners to match each digit card with the right word.

These games spread the word across sight, sound, and movement. Learners see the letter order, say it, and move toward it, which makes the pattern easier to remember.

Quick Reference For Forty In Numbers And Words

By this point you have seen forty in many settings: as a simple number, as part of a larger number, as an age range, and as a decade. The single rule under all of those uses is clear: write forty with “or”, never with “our”.

Here is a compact checklist you can keep beside your notebook or keyboard:

• Need to spell the number 40 in words? Write forty.
• Need the ordinal? Write fortieth.
• Talking about ages from 40 to 49? Write “in his forties” or “in her forties”.
• Talking about years from 1940 to 1949? Write “the nineteen-forties”.
• Joining forty with another digit? Use a hyphen: “forty-six”, “forty-eight”.

If you keep this checklist close, the spelling choice becomes simple. Over time, you will reach the point where only forty looks right on the page, and “fourty” stands out as an obvious error.