Possessive nouns

We use the possessive form of a noun to show something belongs to someone.

After singular nouns , add -'s e.g. This is Sue’s bag. [the bag belongs to Sue]

or

when the noun is plural but doesn’t end in 's' e.g. men’s toilet

After plural nouns, add -s' e.g. Is that the girls' bedroom? [the bedroom belongs to more than one girl]

of can also be used to show possession
e.g. the name of the book, a friend of mine, the teacher of the class