你好！我是你的英语老师。被动语态是中高考英语中的“定海神针”，无论是语法填空、完形填空还是写作，都是必考的高频考点。
今天我们系统梳理【被动语态的基本结构】。请你准备好笔记本，重点关注我标注的“考试陷阱”。
第一部分：被动语态的核心公式
被动语态的基本逻辑是：主语是动作的承受者。
核心公式：主语 + be + 过去分词 (Done) (+ by + 动作执行者)
助记：被动语态看“be”的变化，“done”始终保持不变。
第二部分：八大常考时态的被动语态结构表
这是考试中最基础也最容易丢分的地方，请务必熟记“be”动词在不同时态下的变形。
| 时态 | 被动语态结构 (be + done) | 例句 (以 clean 为例) | 考试频率 |
|---|---|---|---|
| 一般现在时 | am / is / are + done | The room is cleaned every day. | ★★★★★ |
| 一般过去时 | was / were + done | The room was cleaned yesterday. | ★★★★★ |
| 一般将来时 | will be + done / am/is/are going to be + done | The room will be cleaned tomorrow. | ★★★★ |
| 现在进行时 | am / is / are + being + done | The room is being cleaned now. | ★★★★ |
| 过去进行时 | was / were + being + done | The room was being cleaned at 8:00. | ★★★ |
| 现在完成时 | have / has + been + done | The room has been cleaned already. | ★★★★★ |
| 过去完成时 | had + been + done | The room had been cleaned before I arrived. | ★★★ |
| 含情态动词 | 情态动词 (can/must/should...) + be + done | The room must be cleaned at once. | ★★★★ |
第三部分：主动变被动的“三步走”法则
要把一个主动句变为被动句，遵循以下逻辑：
- 宾变主： 将主动句的宾语变为被动句的主语。
- 动变被： 将谓语动词变为“be + done”形式（注意时态一致）。
- 主变宾： 将主动句的主语变为by的宾语（如果不重要可省略）。
第四部分：【高能预警】易错点与考试陷阱
这是资深教师总结的“丢分重灾区”，请重点标记：
1. 消失的“to”要还原（中考高频）
在主动语态中，感官动词（see, hear, watch等）和使役动词（make, let, have）后面接不带to的不定式（即动词原形）。但变为被动语态时，必须还原“to”。
* 主动： I saw him enter the room.
* 被动： He was seen to enter the room. (此处to不可省略)
2. “不及物动词”无被动（高考陷阱）
不及物动词（如 happen, occur, take place, appear, disappear, rise, die）没有宾语，因此绝对不能用被动语态。
* 错误： A car accident was happened. (×)
* 正确： A car accident happened. (√)
3. “主动形式表被动”的特殊动词（高阶考点）
有些动词用主动形式表达被动含义，常考的有：
* 表示属性的动词： sell, wash, write, read, wear, cook。
* 例： The book sells well. (这本书销路好。)
* need / want / require + doing： 相当于 + to be done。
* 例： My hair needs cutting. (= needs to be be cut.)
4. 短语动词的完整性
动词短语（如 look after, take care of, laugh at）变为被动语态时，介词/副词不能丢。
* 主动： They laugh at him.
* 被动： He is laughed at (by them). (at不能丢)
第五部分：名师点拨——考试避坑指南
- 一看主语： 拿到题目先看主语。如果主语是“物”（如 table, book, project），优先考虑被动语态。
- 二看时态： 确定是被动语态后，寻找时间状语（如 yesterday, since 2010, now）来确定“be”的具体形式。
- 三看搭配： 检查是否有固定搭配（如 make sb do → be made to do）。
【课后小练】
请尝试将下列句子改为被动语态：
1. We have finished the work.
2. They are building a new bridge.
(答案：1. The work has been finished. 2. A new bridge is being built.)
希望这份讲义能帮你攻克被动语态！如果有具体题目不理解，随时提问。