6. Unless he believe her, she will be upset.
`->` Unless + S + V(hiện tại đơn), S + will/can/shall + V(infi).
7. If you play with matches, you will be burned.
`->` If + S + V(hiện tại đơn), S + will/can/shall + V(infi).
8. She has done her homework for two days.
`->` for + khoảng thời gian: hiện tại hoàn thành.
`->` S + have/has + VpII.
9. This is the first time I have ever read such an interesting story.
`->` This is the first time + S + have/has + VpII.
10. Although she doesn't sing well, she sings every day.
`->` Although + S + V(chia theo thì thích hợp).
