This document summarizes key points about the passive voice in English grammar:
- The passive voice is formed with an auxiliary verb (to be) and the main verb in the past participle form.
- When changing a sentence from active to passive voice, the subject of the active sentence becomes the object of the passive sentence.
- The agent (the doer of the action) can be omitted from a passive sentence, especially if the agent is unknown, unimportant, or obvious from context.
- All verb tenses can be changed to the passive voice using standard transformations of auxiliary verbs and changing the main verb to the past participle form.