The document discusses the passive voice in English grammar. It explains that the passive voice is used when the actor is unknown or unimportant, and includes the verb "be" plus the past participle form of the main verb. It also notes that in the passive, the subject receives the action and the object of the active sentence becomes the subject. Finally, it lists the different tenses that use the passive voice, formed with combinations of "be" and the past participle.

1. The Passive: be + past participle
We often use the passive when it’s not clear or important who does an action.
My bike has been stolen. (Somebody has stolen my bike. I don’t know who.)
 If you want to say who did the action, use “by”.
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)
 the subject of the active sentence becomes the object of the passive sentence (or is
dropped)
People speak English all around the world.
Subject Verb Object
English is spoken all around the world (by people).
Subject Verb
Present Simple Tense: am/is/are + past participle (V3)
Present Continuous: am/is/are + being + past participle (V3)
Past Simple Tense: was/were + past participle (V3)
Past Continuous: was/were + being + past participle (V3)
Present Perfect: have/has + been + past participle (V3)
Future Tense: will + be + past participle (V3)
Be going to: am/is/are + going to + be + past participle (V3)
Have/Has to: Have/Has to + be + past participle (V3)