We use possessive nouns to indicate ownership. Here are some examples:
That is Tracey's hat.
The children's toys are all over the floor.
James' brother has three motorbikes.
This is Tom and Susan's house.
Megan's brother’s car is very fast.
For singular nouns
Add an apostrophe and an safter the noun: 's
My sister's dress is purple. (The dress belongs to my sister)