In active sentences, the thing doing the action is the subject of the sentence and the thing receiving the action is the object. Most sentences are active. When rewriting active sentences in passive voice, note the following:
- The object of the active sentence becomes the subject of the passive sentence.
- The finite form of the verb is changed (to be + past participle).
a) To be: use the verb “to be” in the same tense as the main verb of the active sentence.
b) Past participle: use the past participle of the main verb of the active sentence.
- The subject of the active sentence becomes the object of the passive sentence (or is dropped).
subject + [to be + Past Participle] + by + agent
You can use the passive form if you think that the thing receiving the action is more important or should be emphasized.
You can also use the passive form if you do not know who is doing the action or if you do not want to mention who is doing the action. Therefore, the phrase “by him” can be omitted: “The door is opened”.
Notice that if the subject of the active sentence is a personal pronoun, the agent in the passive would be the object personal pronoun: me, you, him, her, it, us, you, them.