Instead of saying “the book of somebody”, you can simply say “somebody’s book”. This grammatical feature is called the possessive apostrophe. It facilitates the ability to speak about somebody’s or something’s belongings or characteristics.
When to Put Apostrophe + “s”
This is Julie’s story to tell.
My father and my mother’s cousin share the same birthday.
The cat only caught the mouse’s tail.
Even if you have a singular noun that ends with a sibilant (i.e., the letters “s”, “z”, “sh”, ch”, or “x”), you add an apostrophe + “s” to it.
The box’s surface is very glossy.
You can’t take this seat; it’s James’s!
The same applies for irregular plural forms not ending in these sounds.
The children’s favorite place is the new tree house.
The data’s influence is significantly high this month.
When to Put Just an Apostrophe
Whenever you want to talk about the possessive form of plural nouns that end with a sibilant, you also need to have an apostrophe to indicate the relationship. However, don’t add a second “s” after the apostrophe:
My parents’ wedding must have been quite romantic.
This is our colleagues’ work now.
Exceptions to the Possessive Apostrophe
There are singular nouns that can’t be combined with an additional “’s” as you wouldn’t pronounce the last syllable. Mostly, this is the case with ancient or traditional names of authors or philosophers:
Socrates’ last theory was his best one.
The Israelites were really Moses’ people.
The second exception is possessive pronouns (e.g., mine, yours, theirs). Even though they indicate possession as well, they never get an apostrophe:
This pizza is all ours.
He is a good friend of hers.
This is crucial, since there is room for potential confusion:
- Its (neutral possessive pronoun) versus
- it’s (contraction for “it is”, or “it has”)
- Whose (Question pronoun) versus
- who’s (contraction for “who is”, or “who has”)
The third counterexample is only one word: menswear. Actually, this should include an apostrophe. But it doesn’t, due to traditional spelling.
Lady’s restroom (possible, only refers to one person)
Ladie’s restroom (impossible, ladie doesn’t exist)
Ladies’ restroom (correct, it refers to all ladies)
+ ’s: All singular forms and the plural forms not ending with a sibilant.
...s + ’: All other plural forms (ending with a sibilant)
Exceptions: Some names, possessive pronouns, and menswear
Did you like this article? Fabulous, then perhaps you are interested in LanguageTool’s support, which helps you to write successfully in your everyday life. It offers some interesting alternatives to your word choice, and immediately spots the mistakes in students’, women’s, men’s, and everybody’s texts.
We value your feedback
We’ve made a mistake, forgot about an important detail or didn’t manage to get the point across? Let’s help each other to perfect our writing.