在句子中，我们并不想强调某个人，只要说这个事的时候就喜欢“主动变被动”，突出“事”为主体，弱化“人”。
- Someone has prepared a meal for you. 突出了某人(是谁不重要)事物反而弱化了
- A meal be prepared for you. 改写成被动语态（去掉someone）但时态不一致
- A meal has been prepared for you.体现“已经”（与被改写前的时态一致）
| 普通表达(someone)突出“人” | 被动表达(重点前移)突出“事”为主体，弱化“人” |
|---|---|
| Someone will translate the book into English. | The book will be translated into English. |
| Someone must send a telegram to him. | A telegram must be sent to him. |
| Someone had put out the fire before the fire brigade arrived. | The fire had been put out before the fire brigade arrived. |
| Someone gave the cat some milk to drink. | The cat was gaven some milk to drink. |