Apostrophe in Plural Forms

Summary

Avoid using an apostrophe before the s in a plural, unless necessary to avoid confusion.

Examples
  • There are two i’s in iridescent.
    The plural “i’s” would read as the word “is” without the apostrophe.
  • There are two a’s in abacus.

Most plurals don’t require an apostrophe.

Examples
  • Farley has lost his shoes.
  • The Eriksens went to Vietnam last summer.
  • She won with a pair of nines.

In names of centuries and decades, the apostrophe is optional, though generally omitted in formal writing.

Example
  • the 1800s or the 1800’s

Similarly, although an apostrophe may be used in plurals of abbreviations, numerals, and words that are not nouns, it is usually omitted in formal writing.

Examples
  • SSNs or SSN’s
  • a pair of 9s or a pair of 9’s
  • ifs and maybes or if’s and maybe’s

The apostrophe

An apostrophe is mainly used to indicate possession (the cat’s whiskers, the students’ demands) and contraction (don’t, you’re, it’s). It is rarely used to form a plural, and only when not using it would result in confusion. In this article, we discuss guidelines, examples, and exceptions.

In regular plurals

When you add s or es to a noun to form its plural, don’t insert an apostrophe.

Examples
  • Incorrect:We have hired thirty new employee’s this year.
    Correct:We have hired thirty new employees this year.
  • Incorrect:The volcano’s have all erupted together.
    Correct:The volcanoes have all erupted together.
  • Incorrect:Rita thinks tarantula’s make for wonderful pet’s.
    Correct:Rita thinks tarantulas make for wonderful pets.
  • Incorrect:We have three pony’s on the farm.
    Correct:We have three ponies on the farm.
  • Incorrect:Don’t sit on my spectacle’s!
    Correct:Don’t sit on my spectacles!

With most nouns, an apostrophe is used only to form possessives or contractions.

Examples
  • The employee’s complaints should be addressed.
    the complaints of the employee (possessive)
  • Magma is flowing down the volcano’s slopes.
    the slopes of the volcano (possessive)
  • This employee’s always at her desk.
    employee’s = employee is (contraction)
  • The volcano’s about to erupt!
    volcano’s = volcano is (contraction)

In plurals of words that are not nouns

To form the plural of a word or a phrase not generally used as a noun, add an s without an apostrophe.

Examples
  • I count nine ayes and eleven nays.
  • Her ifs, buts, and maybes will get us nowhere.
  • It was a funny list of dos and don’ts for how to use a toothpick.
  • This pandemic has only widened the gap between the haves and the have-nots.
Caution

Don’t use an apostrophe in yeses and noes. These are regular plural forms of yes (a positive answer or vote) and no (a negative answer or vote).

Example
  • Incorrect: We counted seven yes’s and five no’s.
    Correct: We counted seven yeses and five noes.

Most style guides now recommend omitting the apostrophe from plurals whenever possible. Modern writing favors a sparser punctuation style. However, some writers do prefer the apostrophe, since it can make the plural form of a word not generally used as a noun more readable.

Examples
  • I don’t want to hear any if’s and but’s.
  • The do’s and don’ts are listed in the document.
Tip

Dos and don’ts (without apostrophes for the plurals) is recommended by the Chicago Manual of Style, the Oxford English Dictionary, and the Guardian style guide. The AP Stylebook suggests do’s and don’ts (with an apostrophe for the plural only in do’s). Either style is acceptable.

Example
  • Chicago: Make a list of dos and don’ts.
    AP: Make a list of do’s and don’ts.

Don’t omit the apostrophe for the contraction in don’t.

Example
  • Wrong: dos and donts
    Poor: do’s and don’t’s
    Acceptable: do’s and don’ts
    Acceptable: dos and don’ts

In plurals of abbreviations

In general, avoid using an apostrophe to form the plural of an abbreviation that contains capital letters and no periods.

Examples
  • We need two MBAs and three CPAs in the team.
  • The NGOs have together filed a petition.
  • We have two PhDs in the family.
  • How many ATMs does this bank have?
  • Most CMSs (or CMSes) use our software.

Note that it is not incorrect to use an apostrophe in such abbreviations (ATM’s, PhD’s). But the apostrophe is generally avoided unless necessary in formal writing.

In plurals of abbreviations that contain internal periods, apostrophes can help eliminate confusion.

Example
  • We were asked not to use abbreviations, but I see two e.g.’s in this paper.

In some writing styles, periods are inserted between the capital letters of an abbreviation. An apostrophe is then used to form the plural.

Examples
  • None of the M.B.A.’s and Ph.D.’s could solve the problem.
  • Anita has two B.A.’s and an M.A.

This style is more common in British than in American usage.

In plurals of letters of the alphabet

An apostrophe can help make plurals of capital letters more readable. Using it is optional: the AP Stylebook recommends using the apostrophe; the Chicago Manual of Style suggests omitting it.

Examples
  • AP: Will the A’s, B’s, and C’s please board the flight?
  • Chicago: Do the Xs and Ys really matter?

Always use an apostrophe to form the plurals of lowercase letters.

Examples
  • There are two i’s in miniature.
    Without the apostrophe (“There are two is in miniature“), this sentence would be confusing.
  • The only variables accounted for are the x’s and y’s. What about the z’s?
  • It’ll be painful to be on my p’s and q’s for a whole week.

In plurals of numbers

When numbers are written in words, their plurals are formed like regular English plurals, by adding s or es.

Examples
  • Without the teacher, the class was all at sixes and sevens this morning.
  • They sat in twos and threes, waiting for the band to arrive.

In forming the plurals of numerals, apostrophes are again generally considered superfluous.

Examples
  • Rita has swiped all the 2s and 3s from the game.
  • The left-handed batter hit four 4s in a single over.

Some writers prefer to use an apostrophe: 2’s and 3’s. Both styleswith and without the apostrophe—are acceptable.

In decades and centuries

The names of decades and centuries may be written either with or without an apostrophe.

Examples
  • the 1800s or the 1800’s
  • the 1960s or the 1960’s
Note

Most major style manuals (such as the Chicago Manual of Style, the APA Publication Manual, and the AP Stylebook) recommend omitting the apostrophe in names of decades and centuries.

Examples
  • alternative rock music of the 1990s
  • the discoveries of the 1800s
  • the hippies of the 1960s

Use an apostrophe to indicate that the number denoting the century has been omitted.

Example
  • poetry of the ’80s and ’90s

When the century is omitted from the decade, an apostrophe indicates the omission. Inserting another apostrophe before the s is then inelegant.

Examples
  • Poor: the ’80’s and ’90’s
  • Better: the ’80s and ’90s
Caution

Make sure to use an apostrophe, not an opening quotation mark, to contract the names of decades.

Examples
  • Incorrect:the ‘70s and ‘80s
  • Correct:the ’70s and ’80s

In plurals of names and surnames

To form the plural of a name, add s or es, without an apostrophe.

Examples
  • There are four Nesbits in my class.
  • We are a group of Lucases trying to save the world.
  • The Smiths have left the planet.
  • The Jenningses are getting a new robot.
  • Have the Murphys moved to Mars?

The only time you may need an apostrophe to form the plural of a name is when not using one would be confusing. For instance, both Luca and Lucas are names of people.

Example
  • Poor: There are three Luca’s/Lucas in my class.
    Don’t be afraid to rewrite such a sentence.
  • Better: There are three people named “Luca” in my class.

With names, as with other nouns, an apostrophe is used to form a possessive or a contraction.

Examples
  • Nesbit’s spacesuit is green.
    possessive
  • Nesbit’s reading a book about the moons of Jupiter.
    contraction
Tip

To form the plural of a name ending in y, simply add an s.

Examples
  • We have two Jennies/Jennys in the family.
  • The Murphies/Murphys have adopted a cat from the shelter.

In plural place names

Don’t unnecessarily insert an apostrophe before s in place names that are plural.

Examples
  • Incorrect:Tumkin visited the Philippine’s last year.
    Correct:Tumkin visited the Philippines last year.
  • Incorrect:Lulu lives in the United State’s.
    Correct:Lulu lives in the United States.
Tip

To form the possessive of a plural place name, simply add an apostrophe after the s (without an additional s).

Example
  • Incorrect:the United States’s delegation to the conference
    Correct:the United States’ delegation to the conference

Plural names of geographical features also don’t require an apostrophe.

Examples
  • Incorrect: the Ande’s
    Correct: the Andes
  • Incorrect: the steppe’s of Central Asia
    Correct: the steppes of Central Asia
  • Incorrect: the Isle’s of Scilly
    Correct: the Isles of Scilly

In plurals of italicized terms

Plurals of titles of books, movies, and other works are formed by adding an s. No apostrophe is needed between the italicized term and the s. The title of the work is italicized, but the s that forms the plural is not.

Examples
  • All they have in the waiting room are Washington Posts and Wall Street Journals. Where are the Cosmos?
  • She replied, “We already have seven To Kill a Mockingbirds in our library. Could you donate another title?”
  • There were about twenty Lancets lying on the table.

Note that in formal writing, an editor would rephrase these sentences unless quoting someone verbatim.

Examples
  • She said they already had seven copies of To Kill a Mockingbird in the library.
  • There were twenty copies of the Economist lying on the table.

If an italicized term or title is already in plural form, don’t add another s.

Examples
  • Over the years, I have bought and lost any number of Anne of Green Gables.
  • Several New York Times lay strewn about the study.

Some writers prefer to use an apostrophe before the s. This is not wrong, but an apostrophe is generally not used to form a plural in formal writing unless absolutely necessary. Note that even if an apostrophe is used, it should not be italicized but set in roman.

Example
  • All they have in the waiting room are Washington Post's and Wall Street Journal's. Where are the Cosmo's?

In plurals of quoted text

To form the plural of a word or a phrase in quotation marks, place an s within the quotation marks. Adding it outside can make the text harder to read. An apostrophe before the s, though not incorrect, is generally unnecessary and therefore omitted.

Examples
  • I’ve emailed them a thousand times and am tired of all the “Sorry about the inconveniences.”
    Easier to read than Sorry about the inconvenience”s.
  • Unfortunately, “sorrys” and “thank yous” don’t solve problems; solutions do.
  • How many “for examples” do you count in the text?
  • This series has been ruined by all the “To be continueds.”

Note that rephrasing such sentences is often the better option.

Examples
  • How many times is “for example” used in the text?
  • This series has been ruined by all the episodes ending in “To be continued.”

Using an apostrophe to form such a nonstandard plural is not incorrect, but generally unnecessary.

Examples
  • How many “for example’s” do you count in the text?
  • I’m sick of all their “Sorry about the inconvenience’s.”

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Did You Know?

When or or nor joins the parts of a subject, the verb that follows should agree with the part closest to it.
Know more:Either-Or, Neither-Nor: How to Use Correctly