2018年公共英语一级语法讲解：宾语从句
宾语从句是一种名词性从句，在句中作及物动词的宾语，或介词的宾语，或形容词的宾语。根据引导宾语从句的不同连词，宾语从句可分为三类。
1. 由that引导的宾语从句。that只有语法作用，没有实在的意义，在口语和非正式文体中可以省略。例如：
He said (that) he wanted to stay at home.
She doesn't know (that)she is seriously ill.
I am sure (that) he will succeed.
2. 由连接代词who, whom, whose, what, which和连接副词when, where, why, how引导的宾语从句。这些连接代词和连接副词在宾语从句中充当某个成分。例如：
Do you know who(whom)they are waiting for?
He asked whose handwriting was the best.
Can you tell me where the No.3 bus stop is?
I don't know why the train is late.
3. 由if或whether引导的宾语从句。If和whether在句中的意思是“是否”。例如： I want to know if(whether)he lives there.
He asked me whether(if)I could help him.
【宾语从句歌诀】
宾语从句三姊妹，that，if/whether，wh-/how展风采。
展风采有三关，引导词、语序、时态在把关。
主从时态要一致，陈述语序永不变。
陈述请你选that，疑问需用if/whether连。
特殊问句作宾从，原来问词不用换。
三关过后莫得意，人称、标点需注意。
留意变脸的if/when，从句的简化记心间。
【歌诀解码】
(一)、三姊妹
宾语从句根据引导词的不同可分为三种类型：
1. 由that引导的宾语从句。如
We knew(that)we should learn from each other.
2. 由if/whether引导的宾语从句。如
Please tell me if/whether you have been to America.
3. 由who，where，how等连接代词或连接副词引导的宾语从句。如：
Can you tell me how I can get to the nearest post office?
(二)、三关
1. 引导词关
如果从句是陈述句，引导词用that(that在口语或非正式文体中常省略);如果从句是一般疑问句，引导词用if/whether;如果从句是特殊疑问句，引导词用由疑问词转换而来的疑问代词/副词。
2. 语序关
①陈述句变为宾语从句，语序不变，即仍用陈述语序。如：
He is an honest boy. The teacher said. →The teacher said(that)he was an honest boy.
②一般疑问句和特殊疑问句变为宾语从句，语序变为陈述语序。如：
Does he work hard? I wonder. →I wonder if/whether he works hard.
When did he leave? I don’t know. →I don’t know when he left.
3. 时态关
①如果主句是现在的时态，从句的时态可根据实际情况而定。如：
I have heard(that)he will come back next week.
②如果主句是过去的某种时态，那么从句的时态一定要用过去的某种时态。如： He said(that)there were no classes yesterday.
注意：如果宾语从句表述的是客观真理、自然现象等时，不管主句是什么时态，从句都要用一般现在时。
如： He said that light travels much faster than sound.
(三)、人称的变化和标点的使用
1. 从句的主语如果是第一人称，变为宾语从句则与主句的主语一致;如果是第二人称，则与主句的宾语一致;如果是第三人称，不用变化。如：
“May I use your knife?” He asked me. →He asked me if he might use my knife.
“Do you know her telephone number?” He asked me.
→He asked me if I know her telephone number.
2. 宾语从句的标点均由主句决定。主句是陈述句，用句号;主句是疑问句，用问号。如：
Who will give us a talk? I don’t know. →I don’t know who will give us a talk.
Do you know? Where does he live? →Do you know where he lives?
(四)、两副面孔
if和when既能引导时间状语从句，又能引导宾语从句。因此，遇到它们就要认真分析一下，它们究竟属于“两副面孔”的哪一副。如：
If it rains tomorrow, I won’t come.(时间状语从句)
I don’t know if it will rain tomorrow. (宾语从句)
(五)、从句的简化
1. 当主句谓语动词是find，see，watch，hear等感官动词时，从句常简化为“宾语+宾补”结构，宾补为不带to的不定式或V-ing形式。如：
She found that the wallet was lying on the ground.
→She found the wallet lying on the ground.
2. 当主句谓语动词是hope，wish，decide，forget，plan，agree等，且主句主语与从句主语相同时，从句可简化为不定式结构。如：
She agreed that she could help me with my maths.
→She agreed to help me with my maths.
3. 在连接代词/副词引导的宾语从句中，当从句主语与主句主语或间接宾语一致时，宾语从句可简化为“连接代词/副词+不定式”结构。如：
Can you tell me how I can get to the station?
→Can you tell me how to get to the station?
【习题范例】
1. Miss Green didn’t tell us _______ in 2002.
A. where does she live B. Where she lives
C. where did she live D. where she lived
【解析】答案：D。该题考查的是宾语从句的语序和时态。宾语从句应用陈述句的语序和时态，所以应选D。
2. Would you please tell me ________?
A. when did he come home B. where he would play football
C. if he had seen the film D. why he didn’t watch the game
【解析】答案：D。该题考查的是宾语从句的语序和时态。主句用的实际上是现在时，宾语从句在这个句子里应用陈述句的语序和一般过去时。
3. I don’t know when __________.
A. will the train leave B. the train will leave
C. would the train leave D. the train leave
【解析】答案：B。该题考查的是宾语从句的语序和时态。只有B在语序和时态上符合要求。
4. ---We don’t know _____________. ---It is said that he was born in Sweden.
A. what he is B. if he lives here
C. where he comes from D. which country is he from
【解析】答案: C。该题考查的是宾语从句的语序。按照他们谈论的话题可知：他们说的是某人是哪里人。A和B可以排除掉。D的语序不对，只有C正确。
