1. To walk -> wlaking

2. Has -> have

3. Learns not only -> not only learns

4. When -> since

5. Visited -> has visited

6. Smoke -> smoked

7. To -> as

8. To work -> working

9. Serious -> seriously

10. Could I -> I could

1. Lan didn't feel like walking in rain.

2. It's urgent that she have to go out right now. 

3. She learn not only well but also carefully hoặc :

She not only learn but also sing well ( not only/ but also phải chung 1 mệnh đề)

4. Hoang had felt better when he took the bill

5. This is the first time he have visited HCM Mausoleum.

6. Would you mind if i smoked here?

7. This book is the same with the one which you bought in Saturday

8. I stop working because i'm tired 

9. She was seriously injured in the accident. 

10. Mai asked me if i could sing an English song. 

Gạch dưới là dấu hiệu, tô đậm là sửa nha em 

chúc em học tốt !