1. It has been four years since they used public buses instead of motorbikes.

⇒ It + thời gian + since + QKD

2. He drove so fast that no one could catch him up

⇒ S + V + so + adj + that + S + can/could (not) + V

3. He's having his tattoo done by one of the best experts.

⇒ S + have + O + done + by O

4. If you don't stop talking, you won't understand the lesson.

⇒ Câu điều kiện loại 1

→ If clause → S + don't/doesn't + Vo

→ Main clause → S + will/can/may/should + (be) + Vo/adj

⇒ stop + Ving → dừng làm gì

`1.` It has been four years since they used public buses instead of motorbikes.

`-` Cấu trúc: S`+` have/ has`+` V-ed/ PII`+` since`+` mốc thời gian/ QKD (S`+` V-ed/ PI).

`-` V-ing/ N instead of`+` V-ing/ N: Dùng cái gì/ cái gì thay thế cho. . .

`2.` He drove so fast that everyone can't catch up with him.

`-` Cấu trúc 'Too': S`+` tobe`+` too`+` Adj`+` (for O)`+` To V`+`. . .

`-` Cấu trúc 'So. . . that': S`+` tobe`+` so`+` Adj`+` that`+`MD (S`+` V`+`. . .)

`-` Catch up with sb/ sth: Đuổi kịp với ai/ cái gì?.

`3.` He's having his tattoo done by one of the best experts in the city.

`-` Cấu trúc nhờ vả `+` Áp dụng trong thì HTTD: S`+` tobe`+` having`+` O`+` V-ed/ PII`+` By O

`=` S`+` tobe`+` having`+` N`+` V-ed/ PII`+` O.

`4.` If you don't stop talking, you won't understand the lesson.

`-` Cấu trúc câu điều kiện loại `1`: If`+` S`+` V(s/es), S`+` will/ can/ . . . `+` V-inf.

`-` Stop`+` V-ing: Dừng một việc gì đó.

`-` Stop`+` To V: Dừng `1` việc lại để làm `1` việc khác.