"How old is that boy?"
Translation:ʻEhia makahiki o kēlā keiki kāne?
I think it always comes before the noun it is connected with. This boy, this house. Keia keiki kane. It comes after the noun when it is referring to a noun, but not connected with it. This is the house, this is the boy. Keiki Kane keia.
Please correct me if I am wrong!