* when you called me , i am leading a group of visitors at hoa lo prison
-> When you called me, I was leading a group of visitors at Hoa Lo Prison.
* She was taking outside the imperial Citadel of Thang Long , I explored the palace and other sites inside the Citadel
-> While she was waiting outside the Imperial Citadel of Thang Long, I explored the palace and other sites inside the Citadel.
* Mai wishes she lived in HA NOI so that she can taste many traditional foods
-> Mai wishes she lived in Hanoi so that she could taste many traditional foods.
* Don't you wish you have more time to pay a visit to the Colosseum?
-> Don't you wish you had more time to pay a visit to the Colosseum?
* I wish everybody is aware of the protection of our heritage , so that the future generations can know better about our nation
-> I wish everybody were aware of the protection of our heritage, so that the future generations could know better about our nation.

Sửa lỗi sai:

1. when you called me, I was leading a group of visitors at Hoa Lo prison. (Sử dụng quá khứ tiếp diễn cho cả hai vế câu vì diễn tả hai hành động cùng xảy ra trong quá khứ.)
2. While she was waiting outside the Imperial Citadel of Thang Long, I explored the palace and other sites inside the Citadel. (Sử dụng while để nối hai hành động cùng xảy ra trong quá khứ.)
3. Mai wishes she lived in Hanoi so that she could taste many traditional foods. (Sử dụng could để diễn tả điều ước không có thật ở hiện tại.)
4. Don't you wish you had more time to pay a visit to the Colosseum? (Sử dụng had để diễn tả điều ước không có thật ở hiện tại.)
5. I wish everybody were aware of the protection of our heritage so that the future generations could know better about our nation. (Sử dụng were cho tất cả mọi người và could để diễn tả điều ước không có thật ở hiện tại.)