1) You haven't had enough to eat yet. You ate more yesterday.
2) Why haven't you tidied up your room yet? It to looked really nice last week.
3) Sarah went for a walk with her dog an hour ago. She hasn't come back yet.
4) I haven't seen Jean today, but I saw her yesterday.
5) Yes, I have been to the Lake District before. I went there three years ago.
6) Have you seen Peter? He wanted to walk home with me.
7) Did you see that man on the motorbike yesterday? I have never seen such a dangerous driver.