`1.` They wanted to apologize for their behavior: that's why they paid for dinner. (in order)

`->` They paid for dinner in order to apologize for their behavior.

`=>` in order to/ so as to + Vbare: để làm gì (mục đích)

`2.` It isn't necessary to bring drinks as they are included in the package. (have to)

`->` You don't have to bring drinks as they are included in the package.

`=>` don't have to + Vbare: không cần/ phải làm gì

3. Tom said, "I will be playing tennis when you arrive." (he)

`->` Tom said that he would be playing tennis when I arrived.

`=>` Reported speech: S + said (that) + S + V (lùi thì)

4. When I was a child, I would go to the park every Saturday afternoon. (used)

`->` When I was a child, I used to go to the park every Saturday afternoon.

`=>` used to + Vbare ~ would + Vbare: đã từng làm gì (trong quá khứ)

5. They moved to this suburb in 1990. (lived)

`->` They have lived in this suburb since 1990

`=>` HTHT: S + have/has + V3 + ...

6. Mike was interested in North American history in his school days. (interest)

`->` Mike had an interest in North American history in his school days.

`=>` to be interested in sth ~ have an interest in sth: quan tâm, thích thú điều gì

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