1. Mother has cooked dinner. Wash your hands and go to the dining room.
2. Sally has been cooking dinner for 3 hours.
3. Peter has been repairing his bicycle since 6 pm.
4. Father has repaired my old bike. I can ride it now.
5. I have known George since 2015.
6. Have you learnt the rule?
7. How long have you been learning English?
8. I'm afraid I have lost my key.