`1.` My sister said she tried to learn hard to pass the entrance exam.
Lùi thì: hiện tại đơn `->` quá khứ đơn.
(Không có câu `2`)
`3.` Lan told Lien didn't want to go for a picnic the next day.
Lùi thì: hiện tại đơn `->` quá khứ đơn.
Cụm từ: tomorrow `->` the next day/ the following day.
`4.` My friends told me they had bought a special TV which could perform two different channels at the same time the previous week.
Lùi thì: quá khứ đơn `->` quá khứ hoàn thành.
Cụm từ: last week `->` the previous week.
`5.` Our teacher said you had to wear school uniform the next Monday.
Lùi: have `->` had
Next `->` the next
`6.` The boy said that he had seen the alien the day before when he had been going out with his friends.
Lùi thì: quá khứ đơn `->` quá khứ hoàn thành.
Quá khứ tiếp diễn `->` quá khứ hoàn thành tiếp diễn
Cụm từ: yesterday `->` the day before.
`7.` My friend told me he/ she had just received a birthday gift from his/ her mother.
Lùi thì: hiện tại hoàn thành `->` quá khứ hoàn thành.
`8.` She said the story about that happened long before.
Từ: ago `->` before