We use name + ’s for the possessive: Kate is Lisa’s sister.

NOT Kate is the sister of Lisa.

• For plural nouns, the apostrophe ( ’ ) is after the s:

My parents’ names are Pat and Bill.

• ’s can mean the possessive, is or has:

Bill is Lisa’s father. (’s = possessive)

Kate’s her sister. (’s = is)

She’s got a brother. (’s = has)

• We use whose to ask which person/people a thing belongs to:

Whose mobile phone is that? It’s Tom’s.