Complete the following sentences using if or unless.

1. ……………….. you quit smoking, you will fall ill.

a) Unless
b) If

2. …………………… you do not quit smoking, you will fall ill.

a) If
b) Unless

3. I wouldn’t be alive today …………….. he didn’t help me.

a) if
b) unless

4. …………….. she listened to my advice, she wouldn’t be in trouble now.

a) If
b) Unless

5. …………………… you leave my house at once, I will call the police.

a) Unless
b) If

6. ……………….. he is late, we will go without him.

a) If
b) Unless

7. …………………. he gets caught, he will land in prison.

a) If
b) Unless

8. I won’t be able to do it, ………………… you help you.

a) if
b) unless

9. ………………….. you pay up, we will cancel your subscription.

a) Unless
b) If

10. I will buy it ……………… you lower the price.

a) if
b) unless

Answers

1. Unless you quit smoking, you will fall ill.

2. If you do not quit smoking, you will fall ill.

3. I wouldn’t be alive today if he didn’t help me.

4. If she listened to my advice, she wouldn’t be in trouble now.

5. Unless you leave my house at once, I will call the police.

6. If he is late, we will go without him.

7. If he gets caught, he will land in prison.

8. I won’t be able to do it, unless you help you.

9. Unless you pay up, we will cancel your subscription.

10. I will buy it if you lower the price.