用法详解
宾语从句（Object Clause）是在复合句中充当宾语的从句，通常放在主句的及物动词、介词或某些形容词之后。学习宾语从句需要掌握三个核心要点：引导词、语序和时态。
什么是宾语从句
当一个句子充当另一个句子的宾语时，这个句子就叫宾语从句。
- I know that he is honest.（that 引导的宾语从句）
- Can you tell me where he lives?（where 引导的宾语从句）
- I wonder whether he will come.（whether 引导的宾语从句）
引导词
that 引导的宾语从句
that 引导陈述句作宾语从句，that 在从句中不充当成分，也没有实际意义，通常可以省略。
- He said (that) he would come.
- I believe (that) she is right.
- We know (that) the earth goes around the sun.
注意：当宾语从句的主句谓语是 agree, announce, explain, suggest, insist 等动词时，that 通常不省略；当有多个 that 引导的宾语从句并列时，只有第一个 that 可以省略。
whether / if 引导的宾语从句
whether 或 if 引导一般疑问句作宾语从句，意为"是否"。
- I don’t know whether/if he will come.
- She asked whether/if I liked the movie.
- Can you tell me whether/if there is a hospital nearby?
只能用 whether 不能用 if 的情况：
-
与 or not 直接连用时
- I don’t know whether or not he is coming.
-
在介词之后时
- It depends on whether we have enough time.
-
在不定式之前时
- I can’t decide whether to stay or leave.
-
与动词不定式连用时
- She hasn’t decided whether to accept the offer.
-
主语从句、表语从句、同位语从句中
- Whether he will come is still unknown.
特殊疑问词引导的宾语从句
特殊疑问词（what, who, which, when, where, why, how 等）引导特殊疑问句作宾语从句。
- Can you tell me where you live?
- I don’t understand what he said.
- Do you know how old she is?
- Please show me which book you want.
- I wonder why he left early.
语序
宾语从句必须使用陈述语序，即"连接词 + 主语 + 谓语 + 其他"。
疑问句：Where does he live? 宾语从句：I know where he lives. ✅ 错误：I know where does he live. ❌
疑问句：What is he doing? 宾语从句：Can you tell me what he is doing? ✅ 错误：Can you tell me what is he doing? ❌
疑问句：Who won the game? 宾语从句：Do you know who won the game? ✅ （who 在从句中作主语，语序不变）
时态呼应
宾语从句的时态受主句时态的影响，需要遵循"时态呼应"原则。
主句为现在时态
主句是现在时态（一般现在时、现在进行时、现在完成时）时，从句时态根据实际情况使用任何适当的时态。
- I know that he is busy now.（现在时）
- I know that he was busy yesterday.（过去时）
- I know that he will be busy tomorrow.（将来时）
- I know that he has finished the work.（完成时）
主句为过去时态
主句是过去时态（一般过去时、过去进行时、过去完成时）时，从句要用相应的过去时态。
| 主句时态 | 从句原时态 | 从句变化后 |
|---|---|---|
| 过去时 | 一般现在时 | 一般过去时 |
| 过去时 | 一般过去时 | 过去完成时 |
| 过去时 | 现在进行时 | 过去进行时 |
| 过去时 | 一般将来时 | 过去将来时 |
| 过去时 | 现在完成时 | 过去完成时 |
- He said that he was tired.（原：is）
- He said that he had seen the film.（原：has seen）
- He said that he would come.（原：will come）
- He said that he was doing his homework.（原：is doing）
例外情况
以下情况即使主句是过去时，从句也不用改变时态：
-
从句表示客观真理或自然规律
- The teacher told us that the earth goes around the sun.
-
从句表示习惯性动作
- He said that he gets up at 6 every day.
-
从句中有明确的过去时间状语
- He said that the meeting was held yesterday.
常见句型
Could you tell me…?
用 could 表示委婉请求，不是过去时，从句时态不受限制。
- Could you tell me where the station is?
- Could you tell me how much it costs?
I don’t think/believe/suppose…
当主句谓语是 think, believe, suppose, imagine, expect 等，且主句主语是第一人称时，否定通常转移到主句，这叫"否定前移"。
- I don’t think he is right.（我认为他不对）
- I don’t believe she will come.（我相信她不会来）
- I don’t suppose it matters.（我看这没关系）
- Can you tell me _______? A. where does he live B. where he lives C. where he live
- He asked me _______ I could help him. A. that B. what C. if
- She said that she _______ (finish) the work already.
- Do you know _______ he will come tomorrow? A. that B. whether C. what
- The teacher told us that light _______ (travel) faster than sound.
- B
- C
- had finished
- B
- travels
易错点提醒
- 语序错误：宾语从句必须用陈述语序，这是最常见的错误。
- 时态呼应错误：主句为过去时，从句要相应调整时态。
- 引导词选择错误：陈述句用 that，一般疑问句用 whether/if，特殊疑问句用相应的疑问词。
- 否定前移：I think he isn’t right. ❌ → I don’t think he is right. ✅
- whether 和 if 的混用：注意只能用 whether 的五种情况。
宾语从句是连接简单句和复合句的桥梁，掌握它对提高英语综合能力非常重要。建议同学们多做"简单句合并为复合句"的练习，并注意在口语和写作中尝试使用宾语从句。