一、学习目标
- 理解主语是动作承受者时使用被动语态。
- 掌握 be + 过去分词的核心结构。
- 能根据时态变化 be 的形式。
二、核心概念
| 概念 | 学习时要抓住的意思 |
|---|---|
| 被动语态 | 主语承受动作。 |
| 过去分词 | 被动结构中的动词核心形式。 |
| by 短语 | 必要时说明动作执行者。 |
三、重点知识
| 重点 | 判断方法 | 例句 |
|---|---|---|
| 一般现在时 | am/is/are + done | English is spoken here. |
| 一般过去时 | was/were + done | The bridge was built last year. |
| 情态动词 | modal + be + done | It must be finished today. |
四、知识点讲解
被动语态的关键是同步判断“谁承受动作”和“原句是什么时态”。
1. 学习步骤
- 找主动句宾语，判断它能否作被动句主语。
- 判断原句时态，选择 be 的形式。
- 原谓语动词改为过去分词，必要时加 by。
2. 记忆提示
- 不及物动词通常不能直接变被动。
- 短语动词变被动时，介词或副词不要漏掉。
五、易错点
| 易错点 | 常见错误 | 正确做法 |
|---|---|---|
| 漏 be | The room cleaned every day. | The room is cleaned every day. |
| be 时态错 | The bridge is built last year. | The bridge was built last year. |
| 情态被动漏 be | must finished | must be finished |
六、例题
1. 填空
The homework ___ (finish) tomorrow.
答案： will be finished。
2. 主动变被动
They built the school in 2018.
答案： The school was built in 2018.
七、练习题和答案
1. 练习题
- English ___ (speak) in many countries.
- The window ___ (break) yesterday.
- The task must ___ (finish) on time.
- 把
We plant trees every spring.改为被动语态。 - 为什么
happen一般不直接变被动？
2. 答案
- is spoken
- was broken
- be finished
- Trees are planted every spring.
- 因为 happen 通常是不及物动词，没有直接宾语。