Complete the following sentences using if or unless.

1. I won’t be able to help you ………………… you tell me what is wrong.

a) unless

b) if

2. He should be in his office now …………………… he left early today.

a) unless

b) if

3. ………………… you come now, I am going to leave without you.

a) Unless

b) If

4. …………………. you don’t stop smoking, you will fall seriously ill.

a) Unless

b) If

5. The robber threatened to shoot me …………….. I didn’t give him the money.

a) unless

b) if

6. ………………. you leave at once, I will call the police.

a) Unless

b) If

7. ………………… we miss the last bus, we will have to walk home.

a) Unless

b) If

8. ……………. anyone has found my camera, would they please return it to me?

a) If

b) Unless

9. ………………… Mark didn’t skip his classes, he would achieve better grades.

a) If

b) Unless

10. She asked me ………………. I liked soccer.

a) if

b) unless

Answers

1. I won’t be able to help you unless you tell me what is wrong.

2. He should be in his office now unless he left early today.

3. Unless you come now, I am going to leave without you.

4. If you don’t stop smoking, you will fall seriously ill.

5. The robber threatened to shoot me if I didn’t give him the money.

6. Unless you leave at once, I will call the police.

7. If we miss the last bus, we will have to walk home.

8. If anyone has found my camera, would they please return it to me?

9. If Mark didn’t skip his classes, he would achieve better grades.

10. She asked me if I liked soccer.