If you'd (you would) like to show possession for someone whose name ends with an S, use 's, for example, Chris's holiday was spoiled by rain. And if you'd like to show possession for a plural noun, use the apostrophe without an s, for example, The Jones' lawn is always neat. Check the following examples out:
- They have decided to change Mathias's job (=name that ends with an 's')
- The boss's husband is coming to the office today (=possession for a singular noun ending in 's', like above)
- This is my sister's room (=one sister)
- This is my sisters' room (=more than one sister)
The apostrophe can get really confusing when we try to use it with more complex nouns, like brothers-in-law, for example. Or when two people own the same thing:
- Henry's and Mathilda's roles are going to be discussed tomorrow.
(=2 roles, one belonging to Henry and the other to Mathilda)
- Henry and Mathilda's roles are going to be discussed tomorrow.
(=2 roles, both belonging to Henry and Mathilda. Perhaps they're Henr'salespeople and purchasing agents simultaneously)
- Henry's and Mathilda's cars are nice.
(=2 cars, one Henry's, the other Mathilda's)
- Henry and Mathilda's cars are nice.
(=2 or more cars, belonging to both Henry and Mathilda)