Whose pen is that?
That is his pen.
Whose pencil is that?
That is her pencil.
Whose bag is that?
That is his bag.
Whose pencil case is that?
That is her pencil case.
Whose eraser is that?
That is his eraser.
What is that?
That is her ruler.
What is that?
That is his book.
What is that?
That is her car.