`10.` They have studied English since they were in grade 3

- S + started + V-ing + when + S + V2/V-ed ... :  Ai đó bắt đầu làm gì khi nào..

- S + have/has+ V3 + since+ S + V2/V-ed... : Ai đó làm gì kể từ khi..

`11.` I haven't been abroad before. 

`-` This is the first time + S + have/has + V3... : Đây là lần đầu ai đó làm gì.. 

`-` S + have/has + not + V3 + O + before .... : Ai đó chưa từng làm gì trước đây.

`12.` I last met my aunt when I was 10 years old.

- S + have/has + not + V3 + since + mốc tgian: Ai đó không làm gì kể từ khi ... 

-> S + last + V-ed/V2 + when + S + V2/V-ed : Ai lần cuối làm gì khi...

                   $\color{pink}{\text{kieuank:3}}$

$10.$ They have studied English since they were in grade 3.

-> S + started/began + V-ing + when + QKĐ

= S + have/has + V3/ed + since + QKĐ

$11.$ I haven't been abroad before.

-> This/ It + is the first time + S + have/has + V3/ed

= S + haven't/hasn't + V3/ed + before

$12.$ I last met my aunt when I was 10 years old.

-> S + haven't/hasn't + V3/ed + since + QKĐ

= S + last + V2/ed + when + QKĐ

- Thì QKĐ:

+ Với động từ tobe: 

(+) S + was/were + N/ Adj

(-) S + wasn't/weren't + N/ Adj

+ Với động từ thường:

(+) S + V2/ed

(-) S + didn't + V(bare)