英语被动语态用法核心结构：be + 过去分词 (V3) 主动语态：主语（执行者） + 动词 +

核心结构：be + 过去分词 (V3)

主动语态：主语（执行者） + 动词 + 宾语（承受者）
- 例如：The cat (主语) chased (动词) the mouse (宾语).
被动语态：主语（原主动句的宾语/承受者） + be (变形) + 过去分词 (V3) + (by + 原主动句的主语/执行者)
- 例如：The mouse (主语，原承受者) was chased (be + V3) (by the cat) (执行者).

被动语态的核心使用场景：

强调动作的承受者（而非执行者）：
- 当承受者比执行者更重要、更值得关注时。
  - 主动：Alexander Graham Bell invented the telephone in 1876. (强调贝尔发明)
  - 被动：The telephone was invented in 1876 (by Alexander Graham Bell). (强调电话被发明)
- 新闻标题、科技报告、流程描述中常用，突出事件或事物本身。
  - Thirty people were killed in the earthquake. (强调遇难人数)
  - The new hospital will be opened next month. (强调医院开放)
不知晓或不关心动作的执行者是谁：
- 当不知道谁做了某事，或者谁做的不重要时。
  - My car was stolen last night. (不知道谁偷的)
  - English is spoken here. (谁说的不重要，强调语言使用情况)
  - The road is being repaired. (谁在修路不是重点)
委婉或客观，避免提及执行者：
- 在正式场合、报告或为了显得礼貌、客观时，避免直接指出责任方。
  - A mistake was made in the calculation. (比 Someone made a mistake... 更委婉，不想或不便指出谁犯错)
  - It is believed that... / It is said that... / It is recommended that... (常用固定表达，保持客观)
  - Your application has been received. (官方通知，客观陈述)
描述客观事实、普遍真理或科学原理：
- The heart is located in the chest. (客观事实)
- Water is composed of hydrogen and oxygen. (科学原理)
- Breakfast is served between 7 and 10 am. (常规安排)
正式或学术写作中：
- 为了使文章显得更客观、更注重研究结果或过程而非研究者本身。
  - The experiment was conducted under controlled conditions.
  - Significant differences were observed between the two groups.
  - Further research is needed to confirm these findings.

不同时态的被动语态构成：

被动语态需要将助动词 be 变成对应的时态形式，后面加上主要动词的过去分词 (V3)。

时态	主动语态示例	被动语态示例
一般现在时	They clean the room	The room is cleaned (by them).
一般过去时	They cleaned the room	The room was cleaned (by them).
一般将来时 (will)	They will clean the room	The room will be cleaned (by them).
现在进行时	They are cleaning the room	The room is being cleaned (by them).
过去进行时	They were cleaning the room	The room was being cleaned (by them).
现在完成时	They have cleaned the room	The room has been cleaned (by them).
过去完成时	They had cleaned the room	The room had been cleaned (by them).
将来完成时 (will have)	They will have cleaned the room	The room will have been cleaned (by them).
情态动词 (can, must...)	They must clean the room	The room must be cleaned (by them).
情态动词+完成式	They must have cleaned the room	The room must have been cleaned (by them).

重要注意事项和特殊点：

By 短语：
- 执行者不必总是出现。只有当执行者身份是重要信息时，才用 by + 执行者。
- 使用被动时，首先要考虑是否需要提及执行者。大多数被动句没有by短语。
双宾语动词的被动：
- 有些动词（如 give, send, show, tell, offer, teach）可以接两个宾语（直接宾语-物，间接宾语-人）。
- 这类动词有两种被动形式，可以将其中任何一个宾语变成主语：
  - 主动: Someone gave [him] (IO) [a book] (DO).
  - 被动 1 (以间接宾语为主语): He was given a book (by someone). (更常用)
  - 被动 2 (以直接宾语为主语): A book was given to him (by someone). (需要加介词to/for)
带不定式( to do )的动词的被动：
- 感官动词 (see, hear, observe) 和使役动词 (make, let) 在主动语态后接省略to的不定式，但在被动语态中，必须恢复to：
  - 主动: I saw him cross the street. (cross 前无 to)
  - 被动: He was seen **to** cross the street (by me). (to 必须加上)
  - 主动: They made us work late. (work 前无 to)
  - 被动: We were made **to** work late (by them). (to 必须加上)
-ing 形式的被动：
- being + V3 用于动词后面需要接 -ing 形式的结构中：
  - He hates **being interrupted**.
  - The house needs **painting** / needs **to be painted**. (两种表达方式均可)
  - I remember **being taken** to the zoo as a child.
短语动词的被动语态：
- 许多由“动词 + 介词/副词”构成的短语动词（如 look after, turn down, put off, carry out）可以有被动语态。介词/副词不能省略。
  - 主动: They will **call off** the meeting.
  - 被动: The meeting will be **called off**.
  - 主动: Someone **broke into** my house.
  - 被动: My house was **broken into**.
“Get被动”：
- 在非正式口语中，有时用 get + V3 代替 be + V3，通常表示遭受、事件的发生或强调动作结果（通常不涉及执行者）。
  - He got hurt in the accident. (受伤了)
  - My watch got broken. (表坏了)
  - We got married last year. (结婚 - 强调事件完成)
避免过度使用被动语态：
- 虽然被动很有用，但在强调执行者责任或需要更简洁有力的情况下，主动语态往往更直接、更有力。
- 在写作中，需要根据表达意图灵活选择主动或被动。

总结：

使用被动语态的关键在于判断：

你想要强调什么？（承受者、动作本身，还是执行者？）
执行者是谁重要吗？（不知道？不关心？不便说？）
语体和语境是什么？（正式报告、日常交谈、科技论文？）

熟练掌握被动语态能让你表达更丰富、更精确，更能适应不同的语言环境。练习时多注意不同时态和动词类型的被动形式构造。