Active Voice and Passive Voice

Introduction

Active and passive voice are two ways to express an idea with a difference in focus, achieved by change of word order.

Sentences in the active voice begin with the person or thing that is responsible for doing or performing the action in the verb. In other words, the subject is the doer of the action.

For example, in the sentence

  • The waiter served the food.

the waiter is the one who performed the action of serving the food. 

When we change the active voice to the passive voice, we begin the sentence with the person or thing that received the action (or the object in the original sentence).

In the previous example, the food is the object, so it moves to the position of the subject at the beginning of the passive sentence:

  • The food was served by the waiter.

Here is another example:

  • Active: The employees organized a farewell party for their manager.
  • Passive: A farewell party was organized by the employees for their manager.

The employees in the active voice is the real subject of the verb. When we changed the sentence to the passive voice, the original object, the manager, moved to the subject position.

Usually we add by before the original subject if we believe it is important to complete the meaning. The noun that comes after by is called the “agent.” In the example above, the agent is the employees.

On the other hand, by agent is usually omitted when the subject is unknown, unimportant or obvious from the context. It is also omitted when the subject is somebody, people, or a pronoun (I, you, we, etc.)

  • Active: He will change the light bulb in the morning.
  • Passive: The light bulb will be changed in the morning.

However, by agent is not omitted when the question begins with Who or What (asking about the subject).

  • Active: Who painted the walls?
  • Passive: Who were the walls painted by?
  • Active: What annoyed you?
  • Passive:What were you annoyed by?

Does the verb tense change?

No! When we change a sentence from active to passive voice, we do not change the verb tense. In other words, the present will remain present and the past will remain past, and so on. The change is mainly in the form and word order.

Details of how verb forms change from active voice to passive voice are given in the tables below.

In addition, time/place expressions or prepositional phrases mentioned in the active sentence are kept the same in the passive sentence. This is because the passive sentence conveys the same message but in a different form.

Example:

  • Active: My uncle bought this house three years ago. 
  • Passive: This house was bought by my uncle three years ago.

When is the passive voice used?

Passive voice sentences are used in the following situations.

– When we do not know the real subject (doer of the action)

  • Active: Somebody stole my laptop.
  • Passive: My laptop was stolen.

– When we do not want to mention the doer of the action for one reason or another

  • Active: My brother broke the window in the morning.
  • Passive: The window was broken in the morning.

– When the focus of the sentence is the action rather than the subject

That is why in most scientific texts, the passive voice is used to report the action rather than to state who did it.

  • Active: Scientists have developed several vaccines to combat the disease. 
  • Passive: Several vaccines have been developed to combat the disease.

– When we describe how something is made or done (process description)

  • Active: The chef will cut the vegetables and prepare the sauce.
  • Passive: The vegetables will be cut and the sauce will be prepared.

Form

In all passive voice sentences, there must be one form of the  verb be (be, am, is, are, was, were, been, being) and the past participle of the verb.

verb be + past participle verb

Which verb be to choose?

That will depend on the tense of the active sentence.

  • be: with modals
  • am, is, are: with present simple
  • was, were: with past simple
  • been: with present and past perfect
  • being: with present and past continuous

Subject-verb agreement in the passive voice sentence depends on the new subject of the sentence.

(Find out more about subject-verb agreement here.)

Example:

  • Active: The doctor is checking the blood test results. (The subject is singular, so we use the auxiliary is to agree with it in the present simple.)
  • Passive: The blood test results are being checked by the doctor. (The subject is plural, so the auxiliary are agrees with it in the present simple.)

The following tables detail the different forms of the active voice and passive voice (affirmative, negative, and questions) with examples.

Affirmative Sentences

Active VoicePassive Voice
(1) Subject + present simple verb + object(1) Subject + am / is / are + past participle verb + (by agent)
Salma helps Lubna.Lubna is helped by Salma.
Salma helps the children.The children are helped by Salma.
(2) Subject + present continuous verb + object(2) Subject + am / is / are + being + past participle verb + (by agent)
Salma is helping Lubna.Lubna is being helped by Salma.
Salma is helping the children.The children are being eaten by Salma.
(3) Subject + past simple verb + object(3) Subject + was / were + past participle verb + (by agent)
Salma helped Lubna.Lubna was helped by Salma.
Salma helped the children.The children were helped by Salma.
(4) Subject + present perfect verb + object(4) Subject + have / has + been + past participle verb + (by agent)
Salma has helped Lubna.Lubna has been helped by Salma.
Salma has helped the children.The children have been helped by Salma.
(5) Subject + past perfect verb + object(5) Subject + had + been + past participle verb + (by agent)
Salma had helped Lubna.Lubna had been helped by Salma.
Salma had helped the children.The children had been helped by Salma.
(6) Subject + past continuous verb + object(6) Subject + was / were + being + past participle verb + (by agent)
Salma was helping Lubna.Lubna was being helped by Salma.
Salma was helping the children.The children were being helped by Salma.
(7) Subject + modal + base verb + object(7) Subject + modal + be + past participle verb + (by agent)
Salma will help Lubna.Lubna will be helped by Salma.
Salma will help the children.The children will be helped by Salma.

Negative Sentences 

ActivePassive
(1) Subject + does , do + not + base verb + object(1) Subject + am / is / are + not + past participle verb + (by agent)
Salma does not help Lubna.Lubna is not helped by Salma.
Salma does not help the children.The children are not helped by Salma.
(2) Subject + am / is / are + not + main verb-ing + object(2) Subject + is / are + not + being + past participle verb + (by agent)
Salma is not helping Lubna.Lubna is not being helped by Salma.
Salma is not helping the children.The children are not being helped by Salma.
(3) Subject + did + not + base verb + object(3) Subject + was / were + not + past participle verb + (by agent)
Salma did not help Lubna.Lubna was not helped by Salma.
Salma did not help the children.The children were not helped by Salma.
(4) Subject + has / have + not + past participle verb + object(4) Subject + has / have + not + been + past participle verb + (by agent)
Salma has not helped Lubna.Lubna has not been helped by Salma.
Salma has not helped the children.The children have not been helped by Salma.
(5) Subject + had + not + past participle verb + object(5) Subject + had + not + been + past participle verb + (by agent)
Salma had not helped Lubna.Lubna had not been helped by Salma.
Salma had not helped the children.The children had not been helped by Salma.
(6) Subject + was / were + base verb-ing + object(6) Subject + was / were + not + being + past participle verb + (by agent)
Salma was not helping Lubna.Lubna was not being helped by Salma.
Salma was not helping the children.The children were not being helped by Salma.
(7) Subject + modal + not + base verb + object(7) Subject + modal + not + be + past participle verb + (by agent)
Salma will not help Lubna.Lubna will not be helped be Salma.
Lubna will not help the children.The children will not be helped by Salma.

Questions

A passive Yes/No question starts with an auxiliary.

An information question in the passive voice starts with a Wh-word followed by an auxiliary .

ActivePassive
(1) (Wh) Do / Does + subject + base verb + object?(1) (Wh) Am / Is / Are + subject + past participle verb + (by agent)?
Does Salma help Lubna?Is Lubna helped by Salma?
Does Salma help the children?Are the children helped by Salma?
(2) (Wh) Am / Is / Are + subject + verb-ing + object?(2) (Wh) Am / Is / Are + subject + being + past participle verb + (by agent)?
Is Salma helping Lubna?Is Lubna being helped by Salma?
Is Salma helping the children?Are the children being helped by Salma?
(3) (Wh) Did + subject + base verb + object?(3) (Wh) Was / Were + subject + past participle verb + (by agent)?
Did Salma help Lubna?Was Lubna helped by Salma?
Did Salma help the children?Were the children helped by Salma?
(4) (Wh) Has / Have + subject + past participle verb + object?(4) (Wh) Has / Have + subject + been + past participle verb + (by agent)?
Has Salma helped Lubna?Has Lubna been helped by Salma?
Has Salma helped the children?Have the children been helped by Salma?
(5) (Wh) Had + subject + past participle verb + object?(5) (Wh) Had + subject + been + past participle verb + (by agent)?
Had Salma helped Lubna?Had Lubna been helped by Salma?
Had Salma Helped the children?Had the children been helped by Salma?
(6) (Wh) Was / Were + subject + base verb-ing + object?(6) (Wh) Was / Were + subject + being + past participle verb + (by agent)?
Was Salma helping Lubna?Was Lubna being helped by Salma?
Was Salma helping the children?Were the children being helped by Salma?
(7) (Wh) Modal + subject + base verb + object?(7) Modal + subject + be + past participle verb + (by agent)?
Will Salma help Lubna?Will Lubna be helped by salma?
Will Salma help the children?Will the children be helped by Salma?