Change of Voice

What you need to understand

The object of the active sentence becomes the subject of the passive: the letter becomes the subject of the letter was written.

The doer of the action moves into a phrase beginning with by, and can be left out when it is unknown or unimportant.

The verb be is added in the same tense as the original, and it agrees with the new subject, not with the doer.

The main verb becomes its past participle: written, not wrote or write.

The tense never changes. If the active is in the simple past, the passive is in the simple past.

The pattern for each tense is fixed: is written, was written, will be written, has been written, had been written, is being written, can be written.

Only a verb that takes an object has a passive. Nothing can be done to a sentence like he slept, because there is no object to promote.

A sentence with two objects, such as give, can form two passives: he was given the book, or the book was given to him.

How to work through these questions

Find the object of the active sentence. That is what becomes the subject.

Find the tense of the active verb by looking at the whole verb phrase, not just the main word.

Move the object to the front and use it as the new subject.

Put the verb be into that same tense, and make it agree with the new subject. A plural subject takes are, were or have been.

Add the past participle of the main verb after the form of be.

Add by and the doer at the end, unless the doer is unimportant or unknown.

Read the sentence back and check the tense has not shifted.

Mistakes that cost marks

Changing the tense while changing the voice, so that a present sentence comes out in the past.
Making be agree with the doer rather than with the new subject, which gives the letters is written in place of the letters are written.
Using the base form of the verb instead of the past participle, as in is write for is written.
Getting an irregular participle wrong: written, not writed; taught, not teached; brought, not bringed.
Leaving the object where it was, so that the sentence ends up with two things after the verb.
Trying to make a passive out of a verb that takes no object.

Worked example

The gardener waters the plants. Change this into the passive voice.

The object of the sentence is the plants, so that becomes the subject.
The verb phrase is waters, which is the simple present.
The passive needs the verb be in the simple present, agreeing with the new subject.
The new subject is the plants, which is plural, so the form of be is are.
The past participle of water is watered, which follows are.
The doer, the gardener, is added after by.
The result is: The plants are watered by the gardener. The tense is the simple present in both, as it must be.

Answer: The plants are watered by the gardener.

Practice questions with answers

A few Change of Voice questions with the full solution shown, so you can see how the method is applied before you attempt the timed set.

Question 1

Rewrite in the passive voice: The workers have painted a window.

A A window has been paint by the workers.
B A window has been painted by the workers.
C A window was painted by the workers.
D A window have been painted by the workers.

Answer: Option B — with explanation

The sentence is in the present perfect. To change the voice, the object becomes the subject, the verb *be* is put into the same tense and agrees with the new subject, and the past participle of the main verb follows it. The doer is introduced by 'by'.\nThat gives: A window has been painted by the workers.\nThe other options each break one of those steps. Common mistakes - the sentence is turned into the simple past, which changes the tense as well as the voice: A window was painted by the workers. - the past participle is replaced by the base form of the verb: A window has been paint by the workers. - the verb 'be' agrees with the wrong noun: it agrees with the doer rather than with the thing done to: A window have been painted by the workers.

Question 2

Rewrite in the passive voice: The workers washed a bridge.

A A bridge was wash by the workers.
B A bridge was washed by the workers.
C A bridge is washed by the workers.
D A bridge were washed by the workers.

Answer: Option B — with explanation

The sentence is in the simple past. To change the voice, the object becomes the subject, the verb *be* is put into the same tense and agrees with the new subject, and the past participle of the main verb follows it. The doer is introduced by 'by'.\nThat gives: A bridge was washed by the workers.\nThe other options each break one of those steps. Common mistakes - the past participle is replaced by the base form of the verb: A bridge was wash by the workers. - the verb 'be' agrees with the wrong noun: it agrees with the doer rather than with the thing done to: A bridge were washed by the workers. - the sentence is turned into the simple present, which changes the tense as well as the voice: A bridge is washed by the workers.

Question 3

Which of these is the passive form of: The teacher sang the lamps.

A The lamps were sung by the teacher.
B The lamps were sing by the teacher.
C The lamps are sung by the teacher.
D The lamps was sung by the teacher.

Answer: Option A — with explanation

The sentence is in the simple past. To change the voice, the object becomes the subject, the verb *be* is put into the same tense and agrees with the new subject, and the past participle of the main verb follows it. The doer is introduced by 'by'.\nThat gives: The lamps were sung by the teacher.\nThe other options each break one of those steps. Common mistakes - the sentence is turned into the simple present, which changes the tense as well as the voice: The lamps are sung by the teacher. - the verb 'be' agrees with the wrong noun: it agrees with the doer rather than with the thing done to: The lamps was sung by the teacher. - the past participle is replaced by the base form of the verb: The lamps were sing by the teacher.

Question 4

Which of these is the passive form of: The teacher tested the paintings.

A The paintings were tested by the teacher.
B The paintings are tested by the teacher.
C The paintings were test by the teacher.
D The paintings was tested by the teacher.

Answer: Option A — with explanation

The sentence is in the simple past. To change the voice, the object becomes the subject, the verb *be* is put into the same tense and agrees with the new subject, and the past participle of the main verb follows it. The doer is introduced by 'by'.\nThat gives: The paintings were tested by the teacher.\nThe other options each break one of those steps. Common mistakes - the sentence is turned into the simple present, which changes the tense as well as the voice: The paintings are tested by the teacher. - the past participle is replaced by the base form of the verb: The paintings were test by the teacher. - the verb 'be' agrees with the wrong noun: it agrees with the doer rather than with the thing done to: The paintings was tested by the teacher.

Question 5

Rewrite in the passive voice: The boy has taught the models.

A The models have been taught by the boy.
B The models has been taught by the boy.
C The models have been teach by the boy.
D The models were taught by the boy.

Answer: Option A — with explanation

The sentence is in the present perfect. To change the voice, the object becomes the subject, the verb *be* is put into the same tense and agrees with the new subject, and the past participle of the main verb follows it. The doer is introduced by 'by'.\nThat gives: The models have been taught by the boy.\nThe other options each break one of those steps. Common mistakes - the sentence is turned into the simple past, which changes the tense as well as the voice: The models were taught by the boy. - the verb 'be' agrees with the wrong noun: it agrees with the doer rather than with the thing done to: The models has been taught by the boy. - the past participle is replaced by the base form of the verb: The models have been teach by the boy.

Frequently asked questions

Does the tense ever change?

No. The voice changes and the tense does not. If the active is in the past, the passive is in the past, and any option in a different tense is wrong however well it reads.

When can I leave out the by phrase?

When the doer is unknown, unimportant, or obvious. The letter was delivered is perfectly good English. In a question that asks for the passive of a particular sentence, though, the by phrase is usually kept.

What does be have to agree with?

With the new subject, which is the old object. In the letters are written, are agrees with the letters, the thing written, and not with the person who wrote them.

Can every sentence be made passive?

No. Only sentences whose verb takes an object. Nothing can be done to a sentence like the baby slept, because there is no object to put at the front.

How do I recognise the passive?

It is a form of be followed by a past participle. If you can see be plus a participle, it is passive; if the verb stands alone and has an object after it, it is active.