`1.` Lan said that she would be very busy the day after.

`-` Câu tường thuật: S `+` said to O/told O `+` (that) `+` S `+` V(lùi thì)

`-` Lùi thì: Will `->` Would

`-` Đổi ngôi: I `->` She

`-` Đổi trạng từ: Tomorrow `->` The next day/The day after

`2.` Thu said that all the students would have a meeting the next Sunday.

`-` Câu tường thuật: S `+` said to O/told O `+` (that) `+` S `+` V(lùi thì)

`-` Lùi thì: Will `->` Would

`-` Đổi trạng từ: Next Sunday `->` The next Sunday

`3.` Tam said that he could swim across that river.

`-` Câu tường thuật: S `+` said to O/told O `+` (that) `+` S `+` V(lùi thì)

`-` Lùi thì: Can `->` Could

`-` Đổi ngôi: I `->` He

`-` Đổi trạng từ: This `->` That

`4.` Her father said to her that she could go to the movie with her friends.

`-` Câu tường thuật: S `+` said to O/told O `+` (that) `+` S `+` V(lùi thì)

`-` Lùi thì: Can `->` Could

`-` Đổi ngôi: You `->` She `/` Your `->` Her

`5.` Her classmate said that Lan was the most intelligent girl in her class.

`-` Câu tường thuật: S `+` said to O/told O `+` (that) `+` S `+` V(lùi thì)

`-` Lùi thì: HTĐ `->` QKĐ

`-` Đổi ngôi: Our `->` Her