The passive voice
Learn how to form and use the passive voice in English (be + past participle) with a tense table, clear rules, examples and common mistakes.
In this lesson
The passive voice is a way of building a sentence so that the focus is on the action, or on the person or thing that receives it, rather than on who does it. We form it with the correct tense of be and the past participle: She writes a letter becomes A letter is written by her.
Key point
To make the passive, the object of the active sentence becomes the subject, and the verb becomes be + past participle. Add by + the doer only when this information is useful.
What is the difference between active and passive voice?
In everyday speech, we mostly use the active voice. An active sentence focuses on the subject, the person or thing that does the action. A passive sentence focuses on the action and on what receives it.
Examples
- Active: She writes a letter. (The focus is on the subject, she.)
- Passive: A letter is written by her. (The focus is on the action and the letter.)
When do you use the passive voice?
We choose the passive when the action is more important than the doer. This happens in several common situations.
Examples
- We do not know who did it: My bicycle was stolen last night.
- The doer is obvious or not important: English is spoken in many countries.
- Public messages and notices: Dogs are not allowed.
- Formal or scientific writing: The results were checked twice.
How do you form the passive voice?
Follow these steps to change an active sentence into the passive.
- The passive is formed with the correct tense of the verb be + the past participle of the main verb.
- The object of the active sentence becomes the subject of the passive sentence.
- The active verb changes into the passive form.
- The main verb takes its past participle form.
- The subject of the active sentence becomes the agent, and we introduce it with the preposition by.
- The sentence must have a transitive verb (a verb with an object). Intransitive verbs cannot be changed into the passive voice.
Examples
- Active: The teacher explains the lesson. → Passive: The lesson is explained by the teacher.
- Active: The boys broke the window. → Passive: The window was broken by the boys.
If you are not sure whether a verb has an object, read our lesson on transitive and intransitive verbs.
Common mistake
The accident was happened at night. → The accident happened at night. Happen is intransitive (it has no object), so it has no passive form.
Common mistake
The letter was wrote by her. → The letter was written by her. Use the past participle (written), not the past simple (wrote). Our lesson on regular and irregular verbs lists the forms.
How does the passive change in each tense?
Only the verb be changes to show the tense. The past participle (written) stays the same in every row.
| Tense or form | Active voice | Passive voice |
|---|---|---|
| Present simple | She writes a letter. | A letter is written by her. |
| Past simple | She wrote a letter. | A letter was written by her. |
| Future simple | She will write a letter. | A letter will be written by her. |
| Present continuous | She is writing a letter. | A letter is being written by her. |
| Past continuous | She was writing a letter. | A letter was being written by her. |
| Present perfect | She has written a letter. | A letter has been written by her. |
| Past perfect | She had written a letter. | A letter had been written by her. |
| Infinitive | She has to write a letter. | A letter has to be written by her. |
| Modals | She should write a letter. | A letter should be written by her. |
| Going to | She is going to write a letter. | A letter is going to be written by her. |
Tip
To find the passive form, first write the verb be in the same tense as the active verb (is, was, will be, has been), then add the past participle. If the active subject is he, she or they, the agent becomes by him, by her or by them.
Which tenses are not used in the passive?
Some types of sentences are not normally changed into the passive voice:
- Present perfect continuous tense
- Past perfect continuous tense
- Future continuous tense
- Future perfect continuous tense
Note
Forms such as has been being written are possible in theory, but they sound so awkward that speakers avoid them. Keep sentences in the present perfect continuous tense and the other tenses in this list in the active voice, or choose a different tense.
How do you make negatives and questions in the passive?
For a negative, put not after the first part of be. For a question, move that first part before the subject.
Examples
- The letter was not written by her.
- Was the letter written by her?
- The work has not been finished yet.
- Has the work been finished?
When do you need by in a passive sentence?
Use by + the agent only when the doer is important or is new information: This bridge was designed by a famous engineer. Leave it out when the doer is unknown, obvious or not important: My car was repaired yesterday (we do not need to say by a mechanic).
For more detail, read the Cambridge Dictionary grammar guide to passive forms and the British Council LearnEnglish lesson on passives, which includes extra practice.
Summary
- Passive = be (in the right tense) + past participle.
- The active object becomes the passive subject, and the active subject becomes the agent after by.
- Use the passive when the action matters more than the doer, in notices and in formal writing.
- Only transitive verbs (verbs with an object) have a passive form.
- Perfect continuous tenses and the future continuous are not normally used in the passive.
Frequently asked questions
What is the formula of the passive voice?
The formula is object + be + past participle (+ by + agent), for example: The cake was made by my mother. Only the verb be changes for tense.
Why do we use the passive voice?
We use it when the action or its result is more important than the doer, when we do not know who did it, and in formal writing, notices and news reports.
Can every sentence be changed into the passive?
No. The verb must be transitive, so it needs an object. Sentences with verbs like happen, arrive or sleep cannot be made passive.
Do I always have to use by in a passive sentence?
No. Most passive sentences in real English have no agent. Add by + the doer only when it is important or interesting.
Is the passive voice bad style?
Not at all. It is correct and useful, especially in formal and scientific writing. In stories and everyday speech, the active voice is usually clearer.
