In another article, we address the problem that arises when people try to use apostrophes to make words (especially names) plural.

Here we are dealing with words—both singular and plural—that actually do need to be possessive and thus need apostrophes: Where do they go? When those words end in an “s,” do we add another “s” or not? And what if the words need to be both plural and possessive?

Spotting Confusion with Apostrophes

Can you spot a problem with apostrophes in any of the following sentences?

  1. Bill Sanchez’s report stunned the entire committee.
  2. The Sanchez’s are going on vacation.
  3. The Sanchez’s vacation will begin on Friday.
  4. Jane William’s assistant has been working for the company for three years.
  5. The Williams’s are painting their house.
  6. The Williams’ new car is parked in the driveway.

Only the first sentence is correct. The report belongs to Bill Sanchez.

To make a singular noun possessive, we simply add an apostrophe and an s.

Apostrophes Make Words Possessive, Not Plural

Sentences 2 and 5 are incorrect because the names Sanchez and Williams need to be plural but not possessive. To make a word plural when it ends in a sibilant (s, x, z, ch, or sh), we add es.

Thus, the sentences should have been written this way:

  • The Sanchezes are going on vacation.
  • The Williamses are painting their new house.

First, Decide If a Word Needs to Be Plural

Sentence 3 is incorrect because the vacation belongs to the entire family, not to one person only. We must therefore make the name plural before making it possessive:

The Sanchezes’ vacation will last for two months.

What If a Singular Word Ends In “S”?

Sentence 4 incorrectly places the apostrophe before the s that is part of the name Williams. We should have written “Jane Williams’s assistant.”

When We Add the Additional “S” after Apostrophes

Notice that when we are dealing with a plural noun that ends with s, we do not add the second s to make it possessive.

Most style manuals call for the additional s, however, on singular words ending in s, as in “Paula Jones’s assistant” or “Bess’s dress.”

Add “es” to Words Ending in “S” (or Another Sibilant) to Make Them Plural

In sentence 6, the name Williams needs to be both plural and possessive. To make the plural form of a noun ending in a sibilant, we add es. Thus, we should have written “the Williamses’ new car.”

The Same Rules for Apostrophes Apply to Other Words

While we have used surnames as our examples above, these rules apply also to all nouns that end in sibilants, as in these examples:

  • All of the churches’ steeples had been damaged by the high winds.
  • Both of the old thrush’s wings were now featherless.
  • The soprano’s voice is the highest in the four-part chorus; the bass’s is the lowest.


See if you can identify confusion between plurals and possessives in the following sentences. Some sentences may be correct.

  1. The centerpiece on the banquet table is a gift from the Marsh’s.
  2. Birch’s computer arrived at his office on Friday.
  3. The Barneses’ house overlooks the lake.
  4. The Rogers’ will be out of the country until early July.
  5. Finches’ bills are conical, the perfect shape for crushing seeds.
  6. Over generations of selective breeding, fur farmers changed the foxes red coat to the more commercially desirable white.


  1. Marshes (plural but not possessive)
  2. correct
  3. correct (Add es to the name Barnes to make it plural; then add the apostrophe to make it possessive.)
  4. Rogerses (the plural, but not possessive, form of the name Rogers)
  5. correct
  6. fox’s (one fox) or foxes’ red coats (more than one fox)

Copyright 2001 Get It Write. Revised 2019.