`1.` Liz's vacation in Nha Trang last summer was very wonderful.

`->` Dùng sở hữu (Liz's) trước danh từ (vacation)

`->` in + địa điểm

`->` last summer : DH thì quá khứ đơn

`=>` S + was/were + C.

`2.` Nam could play the guitar when he was small.

`->` could : có thể (quá khứ của "can")

`->` can + V(inf) : có thể làm gì

`->` play the guitar : chơi đàn guitar

`->` when he was small : khi anh ấy còn nhỏ 

`3.` We went on holiday by air to Phu Quoc last summer.

`->` last summer : DH thì Quá khứ đơn

`=>` S + V2(ed/BQT) + O. `=>` go `->` went

`->` go on holiday : đi nghỉ 

`->` by air : bằng đường hàng không

 

 Câu 1 ) Liz / vacation / Nha Trang / last summer / very wonderful

→Liz's vacation in Nha Trang last summer was very wonderful.

Vì last summer : quá khứ đơn

Câu 2 ) Nam / guitar / could / he / small / play / when /.

→He could play the guitar when he was small

Vì when he was small : quá khứ đơn

Câu 3) We / go / holiday / air / Phu Quoc / last summer

→ We went on holiday by air to Phu quoc last summer

Vì Last summer : quá khứ đơn

:(@laphuhai