Is One in a Number Singular or Plural?
Summary
“One in” followed by a number (one in five, one in ten) is grammatically singular, since “one” is singular (one in five adults is stressed by social media). However, such phrases refer not to one person or thing but to a proportion, and the use of plural verbs is acceptable (one in five people are lonely), although singular verbs are preferred in formal usage.
![Graphic titled "Is 'One in...' Singular or Plural?" The left panel shows groups of five, twenty-five, and seventy-five cat-face icons. In each group, twenty percent (or one in five) icons are black and the rest are red. The right panel has the following text. Grammatically singular. (Examples: One in five cats is immune to catnip. [One (in five) is immune.] One in three adults craves simplicity. One in ten people clicks on links.) Plural when based on meaning. (Examples: One in five cats are immune to catnip. [Not one, but twenty percent.] One in three adults crave simplicity. One in ten people click on links.)](https://editorsmanual.com/wp-content/uploads/2022/12/one-in-a-number-media-1024x576.webp)
As singular
When “one in . . .” (one in three, one in five) is the subject of a sentence, a singular verb is traditionally used to agree with the noun “one,” which is singular.
- One in three cars on Nusquam’s roads is electric.
One (in three cars) is electric.
- One in five children still lives in poverty.
- Only one in six students is eligible for a scholarship.
- One in ten patients develops serious symptoms.
- One in five people admits to being a chronic procrastinator.
As plural
Although strict grammatical agreement would dictate use of the singular verb with “one in . . .,” notional agreement (what the writer and reader know is being referred to) allows for use of the plural verb. “One in a number” refers to more than one: for example, “one in five people” is twenty percent of the population, or twenty out of a hundred people. A plural verb can be used to refer to multiple people or things.
- One in three residents here are over the age of 80.
- Only about one in five people infected by the virus show symptoms.
- One in ten patients experience side effects like fatigue during the first week of treatment.
Thus, although “one” is grammatically singular, plural verbs are acceptable with “one in . . .” and often sound more natural, especially with adverbs like about and around, which clearly refer to a plural number.
- Around one in ten people are dyslexic.
- About one in four high-school students require additional coaching.
Additional guidance
In formal styles, “one in . . .” is generally used with singular verbs (one in five is rather than are). The Chicago Manual of Style, for instance, suggests using singular verbs in formal writing, while noting that plural verbs often sound more natural in informal usage.
In news copy and creative writing, both singular and plural verbs are used. In fact, the AP Stylebook recommends using plural verbs in such constructions (one in five are rather than is).
Merriam Webster’s Dictionary of English Usage notes that notional agreement often trumps grammatical agreement in real usage and that writers may refer to a proportion by using a plural verb.
In everyday usage, use either a singular or a plural verb with “one in” followed by a number, depending on whether you want to emphasize “one” or a proportion of the larger set. In formal writing, prefer to use a singular verb.
Examples from published content
Here are some examples from published content that show “one in . . .” used with both singular and plural verbs.
One in five Americans speaks a language other than English at home.
— “The Essential Workers Filling New York’s Coronavirus Wards,” New Yorker (May 1, 2020)One in five reptiles is threatened with extinction.
— Headline, BBC News (Apr. 27, 2022)Almost one in five children . . . attends after-class instruction.
— “Testing Times,” Economist (Dec. 31, 2011)An estimated one in three women experiences it at some point during her lifetime.
— “Sexism and Feminism,” Encyclopedia Britannica (Accessed Dec. 29, 2022)
One in five employers are considering the model.
— “Can Selling Insurance to Patients Transform Health Care?” New Yorker (Oct. 29, 2015)One in five of the top 350 UK companies have been warned about the lack of gender diversity at senior levels.
— “One in Five of UK’s Top FTSE 350 Firms Warned over Gender Diversity,” BBC News (Feb. 29, 2020)One in five working-age people in rich countries suffer from a mental condition.
— “Out of the Shadows,” Economist (Apr. 25, 2015)About one in four Hawaiian workers belong to a union.
— “People of Hawaii,” Encyclopedia Britannica (Accessed Dec. 29, 2022)
One out of . . .
“One out of . . .” means the same as “one in . . .” and is grammatically singular but may be used with plural verbs based on meaning.
- Singular:
Roughly one out of every six American workers commutes more than forty-five minutes, each way.
— “There and Back Again,” New Yorker (Apr. 16, 2007) - Plural:
One out of every 17 novels bought in the U.S. are authored by Patterson.
— “Genius Factories Past and Present,” New Yorker (Aug. 22, 2010)