Look, this is my best friend, Tom.
This is Tom's house.
Look at the two bicycles.
This old one is Tom's.
That new one is Tom's sister, Lily's.
Tom and his sister walk to the ball.
The dog runs to the ball.
Is it the children's ball or the dog's?
Look at those books on the ground.
Whose books are they, Tom's or Lily's?