Bài `2` :

`1.`She has written for 30 minutes.

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

`3.`I haven't seen him for 3 weeks.

`4.`I haven't watched this movie for 6 months.

`5.`She hasn't seen her parents for a long time.

`6.`We haven't gone to this restaurant for 5 months.

`7.`We haven't contacted for 3 months.

* Giải thích :

`a)` S + started/began + Ving/to + V + time

`=`S + have/has + Vpp + since/for + time

`b)` S + last + V2/ed + time ( thời gian trong quá khứ )

`=`The last time + S + V2/ed + was + time

`=`It's + time + since + S (last) + V2/ed

`=`Phủ định của hiện tại hoàn thành : S + have/has not + Vpp + since/for + time

1, She has begun to write for 30 minutes.

begin-began-begun

2, They have studied English since they were in grade 3.

studied là động từ có quy tắc

3, I haven't seen him for 3 weeks.

see-saw-seen

4, I haven't watched this movie for 6 months.

watched là động từ có quy tắc

5, She hasn't seen her parents for a long time.

see-saw-seen

6, We haven't gone to this restaurant for 5 months.

go-went-gone

7, We haven't contacted for 3 months.

contacted là động từ có quy tắc