Is there a computer on the desk?
yes, there is
Is there a pizza?
No, there isn't
Is there a cat in the bathroom?
no, there isn't
Are there 2 grandpas in the living room?
yes, there are
How many cats are there in the bedroom?
There are 2 cats.
Are there any cats on the bed?
Yes, there are
Is there a cat on the sofa?
yes, there is
Are there any elephants in the kitchen?
no, there aren't
How many boys are there in the living room?
There are 2 boys.