被动语态是中考和高考语法填空的必考点：汉语里没有对应的词形变化，学生常在「谁做动作」上转不过弯。抓住一个公式 be + 过去分词，再按时态换 be 的形式，所有被动题都是填空题。
各时态被动式对照表
| 时态 | 主动句 | 被动句 |
|---|---|---|
| 一般现在时 | We clean the room every day. | The room is cleaned every day. |
| 一般过去时 | We cleaned the room yesterday. | The room was cleaned yesterday. |
| 一般将来时 | We will clean the room. | The room will be cleaned. |
| 现在完成时 | We have cleaned the room. | The room has been cleaned. |
| 含情态动词 | We must clean the room. | The room must be cleaned. |
| 现在进行时 | They are cleaning the room. | The room is being cleaned. |
主动变被动三步骤
- 第一步：主动句的宾语提到句首作主语——Paper was invented in China.
- 第二步：谓语改为 be + 过去分词，be 与新主语保持一致
- 第三步：原主语放句尾 by 短语，不重要时省略
- 情态动词保留：The work must be finished today.
- 短语动词整体变被动，介词不能丢：The children are taken good care of.
使用场景：不知道或不必说动作执行者（The thief was caught.）、强调动作承受者（English is spoken all over the world.）。
易错点：不及物动词没有被动语态
被动语态的前提是动词能带宾语，不及物动词 happen、take place、come true、go、arrive 后面没有宾语可提，永远没有被动式。The accident was happened yesterday 是典型错误，正确是 The accident happened yesterday。判断方法：把动词译成中文看能不能直接带宾语——「发生」后面不能接东西，就不能被动。语法填空里出现这类词，主动形式就是答案。