1) I have been waiting for the postman.
2) He hasn't arrived yet.
3) I have been waiting for half an hour for a friend, but he hasn't arrived yet.
4) I have been waiting for an hour but the waiter hasn't arrived yet.
5) Please, don't swallow the cake, you haven't chumped it yet.
6) My new car is parked on the street.
7) They delivered it a few hours ago.
8) I haven't tried it yet.