23. can’t have enjoyed his holiday
(can't have P2: chắc chắn đã không...)
24. may have seen me
(may have P2: có lẽ đã...)
25. needn’t have studied this unit
(needn't have P2: đáng lẽ ra không cần...)
26. shouldn’t have parked outside the train station
(shouldn't have P2: đáng lẽ ra không nên...)
27. shouldn’t have bought the new car
28. could have left the English book at home because it is not here
(could have P2: có thể đã...)
29. may not have meant what she said about you
(must not have P2: chắc hẳn đã không...)
30. must have taken your jacket by mistake
31. must be tired after your cruise
(must be: chắc có lẽ là...)