1. If you don't study harder, you'll fail the next exam.
->Unless you study harder, you'll fail the next exam.
2. If he doesn't practice writing every day, he can't improve his writing skill.
->Unless he practices writing every day, he can't improve his writing skill.
3. Unless this man is a driver, he can't help you move by car.
-> If this man isn't a driver, he can't help you move by car.
4. Unless you go out more often, you might fall ill.
->If you don't go out more often, you might fall ill.
5. If you don't return this book to the library today, you'll have to pay a fine.
->Unless you return this book to the library today, you'll have to pay a fine.
6. Unless he cleaned up the car now, his boss could ask him to do this.
->If he didn't clean up the car now, his boss could ask him to do this.
7. Unless they were absent now, they would meet the headmaster.
->If they weren't absent now, they would meet the headmaster.
8. If I didn't know the number, I would not ring her up.
-> Unless I knew the number, I would not ring her up.
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Unless=If not (không, trừ khi)
*ĐK 1:
- If + S + do/ does+ not + V (nguyên thể)+ O, S + will ()+ V (nguyên thể)
=> Unless + S + V (chia theo S ở thời hiện tại)+ O, S + will+ V (nguyên thể)
- If + S + is/am/are+ not +…, S + will ()+ V (nguyên thể)
=> Unless + S + is/am/are + …, S + will+ V (nguyên thể)
*ĐK 2:
- If + S + did not+ V (chia ở thời quá khứ đơn)+ O, S + would+ V (nguyên thể)
=>Unless + S + V (chia ở thì quá khứ đơn)+ O, S + would+ V (nguyên thể)
- If + S + were/was + not + to + V (nguyên thể)+ O, S + would+ V (nguyên thể)
=> Unless + S + were/was + to V (dang nguyên thể)+ O, S + would+ V (nguyên thể)
