We can use the possessive form of nouns with people or groups of people (e.g. companies),
other living things, places, and times. To make the possessive form of names ending in -s (pronounced /z/) we can add either ' or 's:
• It's Derek Jones' (or Derek Jones's) new sports car.
Put the possessive case
1) This is ( Peter and Kate) book.
2) Let's go to the (Smiths).
3) The (children) room is upstairs.
4) (John) sister is twelve years old.
5) (Susan and Steve) schools are old.
6) (Men) shoes are on the second floor.
7) My (parents) car was not expensive.
8) (Charles) CD player is new.
9) These are the (boys) pencils.