We usually put the marker to before the infinitive. But in some cases the infinitive is used without to.

Test your understanding of infinitives with this grammar exercise. Each question is followed by two suggested answers. Choose the correct one.

1. We don’t allow people ………………………… in the kitchen.

a) to smoke

b) smoke

2. Let him ……………………….. it.

a) do

b) to do

3. You ought ……………………… a doctor.

a) to consult

b) consult

4. I could not …………………………. what she meant.

a) to understand

b) understand

5. I was not allowed ………………………….. it.

a) to do

b) do

6. They made the child ……………………….. the milk.

a) drink

b) to drink

7. I could not …………………….. it properly.

a) see

b) to see

8. I forgot ………………………… my ticket to the airport.

a) take

b) to take

9. I saw him ………………………….. the flowers.

a) to steal

b) steal

10. You don’t need …………………………. it.

a) to do

b) do

Answers

1. We don’t allow people to smoke in the kitchen.

2. Let him do it.

3. You ought to consult a doctor.

4. I could not understand what she meant.

5. I was not allowed to do it.

6. They made the child drink the milk.

7. I could not see it properly.

8. I forgot to take my ticket to the airport.

9. I saw him steal the flowers.

10. You don’t need to do it.