1. bought ( three days ago => quá khứ đơn)
2. Having taken a tower, he went out with his dog
3. She suggested having a year-end party next week.
4. She apologized to her son for taking him to the zoo next Sunday because she had to visit his aunt.
5. Mary said if she caught the plane, she would be home by five.
6. If she attended the meeting, she would know about change of the schedule
7. If I had tried hard enough, I wouldn't have lost the competition
8. The suitcase was too heavy for me to carry.