In the passive voice, a passive subject receives the action of the verb. The bag was punched by Jane. The money was found by me. Passive voice often relies on nominalizations in which the writer changes a powerful action VERB into a weak noun. With few exceptions, you should always try to use active voice.
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Readers like it. The grammar checker on your computer can help you eliminate passive voice. Choose the passive voice when you don't know who did it, your readers don't care who did it, or you don't want them to know who did it. If you're not certain, choose active voice. Your report was lost by Leslie.