1. Use an apostrophe to indicate possession:
a.) With nouns (singular and plural ) that do not end with an s, add an apostrophe and s;
- a salmon’s scales
- sheep’s hooves
- a cat’s tail
b.) With plural nouns ending in s, add only an apostrophe;
- the cats’ tails
- the managers’ duties
c.) With singular nouns that end with s, add either the apostrophe alone or both the apostrophe and s. Whichever method you choose, stick to it.
- Charles’ hat OR Charles’s hat
- Brussels’ population OR Brussels’s population
d.) If possession is common to two or more individuals, only the last name takes the apostrophe;
- John and Jane’s car
- Polly and Peter’s house
However, we make each noun possessive if possession is not common;
- We sells men’s, women’s and children’s bikes.
- We will read both John’s and Jane’s letters.
e.) Try to avoid using the possessive apostrophe in the following cases:
With inanimate objects
The Eiffel Tower’s lights
- The lights of the Eiffel Tower
I enjoyed War and Peace’s ending
- I enjoyed the ending of War and Peace
2. Use an apostrophe in contractions to indicate missing letters and numbers:
- can’t, won’t, it’s, the summer of ’92 ,etc.
3. Use an apostrophe with nouns followed by a gerund:
- The old man’s swimming was still strong and fast.
- The crowd loved Jane’s singing.