Sentences with modal verbs

Study the following sentences.

This will solve our problem.

We can change this sentence into the passive.

Our problem will be solved by this.

Passive sentences of this kind have the following structure: auxiliary verb + be + past participle.

This new drug should treat cholera.

Cholera should be treated by this new drug.

You will have to seek his help.

His help will have to be sought by her.

Now read the following sentence.

They would have completed the work. (Active)

The work would have been completed by them. (Passive)

She could have solved the problem.

The problem could have been solved by her.

These sentences have the following structure in the passive: auxiliary verb + have + been + past participle.

Exercise

Change the following active sentences into the passive.

1. She may accept the proposal.

2. You must separate the infected children from the rest.

3. You cannot draw water from a well with a sieve.

4. He could not contact his parents.

5. You should not underestimate the value of exercise.

Answers

1. The proposal may be accepted by her.

2. The infected children must be separated from the rest.

3. Water cannot be drawn from a well with a sieve.

4. His parents could not be contacted by him.

5. The value of exercise should not be underestimated by you.

Notes

Passive structures are not preferred in business writing because they put no emphasis on the doer of the action. However, in academic writing they are quite common.