2. Going out late at night is dangerous

→ Ving đứng đầu câu làm chủ ngữ.

→ It's + adj + to V ⇔ Ving + is + adj

3. Student mustn't play football in the school yard.

→ must + V: phải làm gì ⇔ mustn't + V: cấm làm gì

4. The last time John played computer games was two month ago.

→ S + has/have + V3/ed  + for + time

⇔ The last time + S + V2/ed + was + time + ago

5. Mary has played the guitar since she was five years old.

→ S1 + began/started + Ving + when + S2 + V2/ed

⇔ S1 + has/have + V3/ed + since + S2 + V2/ed 

2 Going out late at night is dangerous.

`-` Ving + O + be + adj: Làm điều gì thì như thế nào.

3 Students must not play football in the school yard.

`-` S + must + Vinf + O: Ai đó phải làm gì.

4 The last time John played computer games was two months ago.

`-` The last time + S + V(qk) + O + be + time: Lần cuối ai đó làm gì ...

5 Mary has played the guitar since she was five years old.

`-` S + have/has + Vpp + O + time: Ai đó làm gì được bao lâu.