Buy car and house

On the way to school......

Me: Mummy, why uncle and aunty stand by the roadside?
Mummy: They're waiting for bus.
Me: Why they need to wait for bus?
Mummy: Because they no car.
Me: Why they no buy car?
Mummy: Because the car is very expensive.
Me: Ooo.... Mummy, we cannot buy the house, too!
Mummy: Oh yes, the house is also very expensive...
Me: No..... The house is too big, cannot put inside the trolley (shopping cart)!
Mummy: Why you need to put inside the trolley?
Me: I go to shopping buy things need to put in the trolley. The house is too big, the car is too big, That's why we cannot buy.....
Mummy: ('Good' reason...)