40 in Words: How to Spell Forty and Use It Correctly

The number 40 in words is written as forty. The correct spelling is f-o-r-t-y. It represents four tens and can function as a cardinal number in phrases such as “forty participants,” “forty pages,” or “forty days.” Do not write fourty; that form is a common misspelling even though the related number four contains the letter u. In a sentence, capitalize the word only when it begins the sentence or appears in a title that follows title-style capitalization. For example, “The study included forty participants” uses lowercase, while “Forty participants completed the survey” begins with a capital letter. Whether you should use the word forty or the numeral 40 depends on the style guide and context. Academic styles commonly prefer numerals for 10 and above, but a number at the beginning of a sentence is usually spelled out or the sentence is recast. Always follow the requirements of your university, journal, publisher, or client.

Forty is correct; fourty is incorrect in standard modern English. The confusion is understandable because four, fourteen, and fourth retain the letter u. However, the established spelling of the multiple of ten is forty. A spellchecker will normally flag fourty, but writers should still learn the form because the error can remain in names, quoted text, file labels, or systems with limited language checking. When proofreading, search the entire document for “fourty,” including tables, figure captions, appendices, and references to survey ages or sample sizes. Replace it with “forty” unless you are reproducing an exact historical quotation or proper name. If a quotation contains the misspelling, follow the relevant quotation rules rather than silently altering a source. In your own prose, the safe rule is simple: use forty every time you mean the number 40.

Use the form required by the applicable style guide. In APA Style, numerals are generally used for numbers 10 and above, so 40 participants is normally appropriate. Other editorial systems may spell out numbers that can be expressed in one or two words, while technical and scientific writing often favors numerals for quick comparison. Context also matters. Measurements, ages, percentages, dates, times, scores, statistical values, and numbers in tables are frequently written as numerals. A number at the beginning of a sentence is usually spelled out, so “Forty participants responded” is acceptable, although “A total of 40 participants responded” may read more smoothly. Do not switch randomly between forty and 40 for comparable information. Check your university handbook, target journal instructions, or publisher style sheet, then apply the chosen rule consistently. When a rule has an exception, prioritize clarity and the specific convention for that type of data.

The ordinal form of 40 is written fortieth, not fourtieth. The spelling changes from the cardinal word forty by replacing the final y with ieth. You can write “the fortieth participant,” “the fortieth anniversary,” or “the fortieth page.” The numeral form is 40th. Choose between fortieth and 40th according to the document’s style and the surrounding context. In formal prose, the word may be suitable when the expression is not technical or when it begins a sentence. In tables, headings, timelines, and compact labels, 40th may be easier to scan. Avoid adding an incorrect suffix such as 40st or writing 40-th. If the ordinal is part of an official event name or edition title, reproduce the organization’s preferred form. As with cardinal numbers, consistency matters across the text, captions, tables, and supplementary files.

Use forty as a cardinal number before a countable noun or as a standalone number. Examples include “Forty students attended the workshop,” “The interview lasted forty minutes,” and “The final sample contained forty records.” When the sentence begins with the number, spelling it out prevents an awkward numeral at the start. Within a scientific sentence, however, a numeral may be more appropriate: “The sample contained 40 records.” If several quantities are being compared, keep their presentation parallel instead of writing “forty participants in Group A and 52 in Group B.” You could write “40 participants in Group A and 52 in Group B.” Also distinguish forty from forties. The plural form can refer to the numbers or years from 40 to 49, as in “participants in their forties.” It does not take an apostrophe unless possession is intended. Read the whole sentence aloud and check the governing style guide before making the final choice.

Hyphenate compound number words from twenty-one through ninety-nine when they are written out and are not exact multiples of ten. Therefore, 41 is forty-one, 42 is forty-two, and 49 is forty-nine. The number 40 by itself is simply forty and takes no hyphen. In a larger spelled-out number, the compound portion still carries the hyphen: 140 may be written “one hundred forty,” while 145 may be written “one hundred forty-five” in a style that omits and. Conventions for including and vary by regional and editorial style. Hyphens are also relevant in some compound modifiers, such as “a forty-page report,” where forty-page jointly modifies report. Do not hyphenate the same phrase when it follows the noun: “The report was forty pages long.” These distinctions make relationships between words clear.

On a cheque or payment document, write the amount in words exactly as the form and local banking convention require. For a whole amount of 40, the wording may be “Forty only” or “Forty and 00/100,” depending on the currency and document format. Add the currency name when the form expects it, such as “Forty rupees only” or “Forty dollars and 00/100.” The spelling remains forty, never fourty. Draw a line through unused space if the institution recommends it, and ensure the numeric box matches the words. Do not rely on a general language article as a substitute for bank instructions because cheque formats and legal conventions vary by country and provider. If an amount includes decimals, confirm how the fractional part should be represented. For academic examples involving financial documents, label the example clearly and avoid presenting one regional format as universal.

Normally, forty is lowercase. Capitalize it at the beginning of a sentence, as in “Forty respondents completed both surveys,” or when a title uses a capitalization style that requires major words to begin with capitals. It may also appear capitalized as part of an official proper name. In ordinary running text—“the study included forty cases”—lowercase is correct. Capitalization does not change simply because the number is important or because it appears in a result. In table headings and labels, follow the capitalization system used throughout the table. If writing a heading in sentence case, use lowercase unless forty is the first word. If writing in title case, consult the prescribed title rules. Academic editing should address capitalization consistently, not word by word in isolation. Search matching headings and captions to ensure the same type of expression follows the same editorial treatment.

Most formal editorial guidance advises against beginning a sentence with the numeral 40. You can spell it out—“Forty participants completed the first stage”—or revise the sentence—“A total of 40 participants completed the first stage.” Recasting is often better when the opening expression is long, contains a decimal, or belongs to a statistical statement. For example, instead of spelling out a complicated percentage, start with “The results showed that…” and retain the numeral later in the sentence. Tables, lists, slide labels, and intentionally compact formats may follow different conventions. Also consider consistency: if the surrounding paragraph compares 40, 52, and 68 participants, recasting the first sentence allows all three quantities to remain as numerals. Do not apply a sentence-opening rule mechanically if it makes the prose harder to read; use the form that satisfies the governing style and communicates the data clearly.

Yes. Contentxprtz can review number presentation as part of relevant academic editing or proofreading support. An editor can check whether numerals and number words follow the requested journal or university style, whether sentence-opening numbers are handled clearly, and whether forms such as forty, fortieth, and hyphenated compounds are correct. The review can also examine consistency across running text, tables, captions, abstracts, appendices, and supplementary material. This is most useful when number style is one part of a broader language or formatting problem rather than the only change required. Authors should provide the target style guide or journal instructions and remain responsible for verifying data, calculations, units, statistical results, and final submission requirements. Editing can improve clarity and consistency, but it cannot validate unsupported findings or guarantee acceptance. A focused research-paper edit may be appropriate when the document also needs grammar, flow, terminology, and presentation checks.