In a passive sentence, the focus is on what happens to something, not on who does it. You use be and a past participle.
| Active | Passive |
|---|---|
| Workers build the house. | The house is built by workers. |
| Someone stole my bike. | My bike was stolen. |
In the active, the doer is the subject. In the passive, the thing affected is the subject. The object of the active sentence becomes the subject of the passive sentence.
A past participle is the third form of the verb: built, stolen, made, written. See The present perfect: form and uses. Only be changes with the tense.
| Tense | Positive | Negative | Question |
|---|---|---|---|
| Present simple | The room is cleaned daily. | The room isn't cleaned daily. | Is the room cleaned? |
| Past simple | The room was cleaned. | The room wasn't cleaned. | Was the room cleaned? |
| Present simple, plural | The rooms are cleaned daily. | The rooms aren't cleaned daily. | Are the rooms cleaned? |
Short answers: Was the room cleaned? Yes, it was. / No, it wasn't.
You can add by + the doer when it matters or is new information.
There are three main reasons.
The other tenses are on The passive in many tenses and with modal verbs.
✗The house built in 1990.
✓The house was built in 1990.
This sentence needs a form of be: was built.
✗The room cleaned every day.
✓The room is cleaned every day.
In the present simple passive, use am, is or are before the past participle.
✗The cake was ate by the children.
✓The cake was eaten by the children.
After be, use the past participle: eaten.
✗The letter was wrote yesterday.
✓The letter was written yesterday.
After be, use the past participle: written.
See The passive in many tenses and with modal verbs, Advanced passives: get-passive, be supposed to and more and The present simple. For the past, see The past simple.
Eight questions. Choose one answer for each.