Ex3: Tìm lỗi sai và sửa lại cho đúng :
1. are -> is
2. is -> are
3. costed -> costs
4. are -> is
5. are -> is
6. are -> is
7. are -> is
8. seem-> seems
9. were -> was
10. is -> are
11. are -> is
12. is -> are
13. is -> has been
14. is -> are
15. are -> is
16. speaks -> speak
17. are -> is
18. are -> is
19. were -> was
20. were -> was
Ex4: Điền vào chỗ trống một từ thích hợp :
1. is
2. eat
3. are
4. is
5. are
6. is
7. is
8. is
9. is
10. have