Who acts, and who receives the action?
In typical action examples, compare the agent with what the action affects: A neighbour feeds our cat → Our cat is fed by a neighbour. In the active, the neighbour is the subject; in the passive, the cat is. Do not identify voice solely by how active the subject seems: an active sentence can also describe a state, as in He knows the answer.
To describe an action without naming who performs it, English can make the recipient the subject and add be + past participle: Our cat is fed. The cat receives the action, while the person feeding it need not be identified.
Not every sentence can be made passive: if the action has no object, there is no recipient available for this transformation.
A neighbour feeds our cat every summer.
A neighbour feeds our cat every summer.
The subject a neighbour performs the action, so the sentence is active.
Our cat is fed every summer.
Our cat is fed every summer.
Now the subject our cat receives the action, and the person feeding it is not named.
The train left at six.
The train left at six.
The action has no object, so this sentence has no passive counterpart.
Turning an active sentence into a passive one
The transformation has three steps. The object of the active sentence becomes the subject of the passive. The verb becomes be + past participle, with be carrying the tense of the active verb. The agent is either omitted or retained after by.
The rest of the meaning stays the same: the place, time, and number of participants remain unchanged. The transformation changes the perspective of the message, not the facts.
object + be + past participle (+ by + doer)
- V3 / past participle —
- The third verb form: worked, gone, seen. Used after have/has or in the passive, for example; it is not always the same as V2.
- object / O —
- Who or what an action affects: in I read a book, a book is the object.
The police found the car.
The police found the car.
The active version: the agent is named as the subject.
The car was found.
The car was found.
The object the car becomes the subject, and the agent is omitted.
The car was found by the police.
The car was found by the police.
The same passive, with the agent retained after by.
Be marks tense and agrees with the new subject
In these passive patterns, only be changes. The past participle of the main verb remains the same across the forms.
In the present, I takes am; he/she/it or a singular noun takes is; and you/we/they or a plural noun takes are. In the past, I/he/she/it takes was and you/we/they takes were. You takes are/were even when referring to one person.
am/is/are + V3 (present); was/were + V3 (past)
- V3 / past participle —
- The third verb form: worked, gone, seen. Used after have/has or in the passive, for example; it is not always the same as V2.
This room is booked every Friday.
This room is booked every Friday.
One room and a regular present action call for is.
These rooms are booked every Friday.
These rooms are booked every Friday.
There are several rooms, so be becomes are, while booked stays the same.
The hall was booked for one evening.
The hall was booked for one evening.
One hall and a completed past event call for was.
When the agent is not named
A passive without by is an ordinary form, not a shortened substitute. The agent is omitted in three typical cases: it is unknown, obvious from the situation, or simply unimportant to the message.
This is why the passive is common in announcements, news, and reports of problems: the listener needs a fact about something rather than the name of the person involved.
My wallet was found in the street.
My wallet was found in the street.
The agent is not named. It may be unknown, understood, or simply unimportant; the sentence itself does not explain the reason for omission.
The rubbish is collected on Tuesdays.
The rubbish is collected on Tuesdays.
The agent is obvious, so there is no need to name the collection service.
The results were sent to every student.
The results were sent to every student.
The agent is unimportant: the students care about the fact that the results were sent.
When by + agent is needed
Keep the by-phrase when the agent is the news. The passive then lets you begin with the topic of discussion while still naming who performed the action.
Be careful with by: the preposition has other meanings too. In a sentence about transport or a deadline, by does not name an agent, so the word alone does not make a sentence passive.
This wall was decorated by local children.
This wall was decorated by local children.
The wall remains the topic, but the people who decorated it are the main news, so they are named after by.
The music was chosen by the students themselves.
The music was chosen by the students themselves.
Removing the by-phrase would lose the most important part of the message.
He goes to work by bus.
He goes to work by bus.
Here by indicates the means of transport, not an agent; the sentence is active, with he as the person travelling.
Which object can become the subject?
In an ordinary transformation, the active object becomes the passive subject: They ate the sandwiches → The sandwiches were eaten. The intransitive The accident happened has no such object.
Sometimes the object belongs to a verb with a preposition: They laughed at him → He was laughed at. Do not therefore rule out words such as laugh or sleep in every passive construction; check the whole pattern. This lesson focuses on simple transitive verbs.
The children ate all the sandwiches.
The children ate all the sandwiches.
There is an object, all the sandwiches, so a passive is possible.
All the sandwiches were eaten.
All the sandwiches were eaten.
The object becomes the subject, and the children are not named.
The accident happened at nine.
The accident happened at nine.
Happen has no object, so there is no passive counterpart.
Choosing a voice for your own message
Voice lets you choose the topic. Begin with what the message is really about: the person if the person matters, or the thing or event if that is what matters.
Active and passive can alternate in a connected text. Choose according to the topic and the emphasis you need. Several passive sentences in a row can also be appropriate, for example when describing a process; their number alone is not enough to call a text artificial.
My teacher wrote this note.
My teacher wrote this note.
The active structure makes the teacher the subject. Whether the writer or the note is new information depends on the preceding conversation.
This note was written on Monday.
This note was written on Monday.
The passive begins with the note and states the day it was written; the writer is not identified.
Nothing was decided at the meeting.
Nothing was decided at the meeting.
The passive reports the outcome without naming the participants.
Common mistakes
Incorrect:Thousands of tourists are visited this castle.
Correct:Thousands of tourists visit this castle.
The tourists perform the action, so active voice is needed. Be + past participle would make them the people being visited.
Incorrect:My suitcase were left at the airport.
Correct:My suitcase was left at the airport.
Be agrees with the new subject: one suitcase takes was, not were.
Incorrect:The email was send to all students.
Correct:The email was sent to all students.
Be needs the past participle sent, not the base form send, in this passive construction.
Incorrect:The shelves are clean every Friday by the staff.
Correct:The shelves are cleaned every Friday by the staff.
To express the action of cleaning the shelves, use cleaned after are. Clean can be an adjective describing their state, but it does not express the passive action of cleaning in this sentence.
Incorrect:The concert was happened in July.
Correct:The concert happened in July.
Happen has no object and therefore has no passive form here; the concert simply happened.
Incorrect:Did the boxes moved to the second floor?
Correct:Were the boxes moved to the second floor?
In this passive question, be itself is the auxiliary, so the question starts with were; did is unnecessary.