Ответ:
1. has not been speaking since he has returned
2. has been speaking when he returned
3. has been cooking
4. has been cooking, then she had, left
5 and 6. i have already bought
7. i have known
8. i known
9. you sent
10. you have sent
11. i have read
12. i read
13. have you stayed
14. have you been staying
Объяснение: