`1.` What are your plans for the weekend ? ( do )

`->` What are you going to do for the weekend?

`*` Tạm dịch: Bạn sẽ làm gì vào cuối tuần?

`2.` Peter knew how to skate when he was 12 . ( could )

`->`  Peter could skate when he was 12.

`*` Tạm dịch: Peter có thể trượt băng khi mới 12 tuổi.

`3.` The last time they visited Europe was two years ago . ( not )

`->`  They have not visited Europe for two years.

`*` Tạm dịch: Họ đã không đến thăm châu Âu trong hai năm.

1. What are your plans for the weekend? ( do )

What do you plan for the weekend?

=> What do/ does + S + V?

2. Peter knew how to skate when he was 12. ( could )

Peter could skate when he was 12

=> could( thể quá khứ của ''can''): có thể

3. The last time they visited Europe was two years ago. ( not )

They haven’t visited Europe for two years

=> Hiện tại hoàn thành ( thể phủ định) : S + haven't/ hasn't + Vpp