Grammar Monster
Grammar Monster

Apostrophe Placement Rules (Grammar Lesson)

Apostrophe Placement Rules

You can use an apostrophe and the letter s to show possession. This page covers the rules governing the placement of the apostrophe.

When using an apostrophe for possession, the first thing to think about is whether the possessor is singular or plural. This is important because it determines where the apostrophe is placed. Here are some examples with the possessors highlighted:
  • The seagull's wings.
  • (With one seagull, the apostrophe is placed before the s. In other words, you have to add 's.)
  • The seagulls' wings.
  • (With two or more seagulls, the apostrophe is placed after the s; i.e., add just '. (Note: The s will already be there in a plural word that ends s.)

With a Singular Possessor, Place the Apostrophe before the S

When the possessor is singular, add 's. For example:
  • Wagner's music is better than it sounds. (Mark Twain)
  • A friend's eye is a good mirror.

With a Plural Possessor, Place the Apostrophe after the S

When the possessor is plural, add ' after the s. For example:
  • The dogs' dinner smells better than ours.
  • The ladies' mobile phones were confiscated until after the show.

An Exception (Plural Nouns Not Ending S)

For plural words not ending s (e.g., men, people, children), add 's(like they were singular). For example:

  • Zeus does not bring all men's plans to fulfilment. (Homer, 800-700 BC)
  • All television is children's television. (Richard P. Adler)

Another Exception (Singular Nouns Ending S)

For singular words ending s (e.g., Wales, Wells, Jesus), you have a choice. You can add ' or 's. The general rule is write it how you would pronounce it. For example:
  • Jones's briefing was excellent.
  • (If you would say Jonesiz briefing, use Jones's.)
  • Jones' briefing was excellent.
  • (If you would say Jones briefing, use Jones'.)

Another Exception (The Possessive Form of Compound Nouns)

With compound nouns (e.g., father-in-law), add 's to the end. It does not matter is the compound noun is singular or plural. For example:
  • Her sister-in-law's motive was financial.
  • (This is the motive of one sister-in-law.)
  • Her sisters-in-law's motive was financial.
  • (This is the motive of two or more sisters-in-law.)
Read more about the plurals of compound nouns.

A Quirk (Apostrophes with Joint and Individual Ownership)

With joint ownership, make the last word in the series possessive. With individual ownership, make both parts possessive (or all parts if there are more than two). For example:
  • Jack and Simon's cars
  • (With joint ownership, only the last part is possessive.)

  • Jack's and Simon's cars
  • (With individual ownership, both parts are possessive.)
    (Note: It will be assumed that Jack has one car and Simon has one car. If this is not the case, then another construction is required. "Jack's cars and Simon's cars" is one option.)
Top Tip

It's Only about the Number of Possessors

Where to put the apostrophe is only determined by the number of the owner. It doesn't matter whether the thing being owned is singular or plural.
  • hamster's toy
  • hamsters' toy
  • hamster's toys
  • hamsters' toys
In these examples, only the number of hamsters is relevant. The number of toys is irrelevant.

Interactive Test

See the tests on the placement of apostrophes.

The History of the Possessive Apostrophe

The principal function of an apostrophe is to replace a missing letter (e.g., don't, isn't). This is related to the possessive apostrophe.

In old English, possession was shown by adding es to the possessor regardless of whether the possessor was singular or plural. For example:
  • hamsteres toy
  • hamsterses toy
  • peoplees poet
Over time, the e was replaced by an apostrophe and if that left an ending of -s's, then the second s was removed.

This process still works for everything. There are no exceptions.

(1) Add es to the possessor
(2) Replace the e with '
(3) If left with s's, change to s'

Read more about using apostrophes.