宾语从句是一个句子在复合句中起宾语的作用，它既可作谓语的宾语，也可作介词的宾语。宾语从句由从属连词that，if，whether，连接代词who，whom，whose，what，which或连接副词when，where，how， why引导。
（1）宾语从句的引导词
①陈述意义的宾语从句由从属连词that引导，that本身没有词义，引导词在从句中不担任从句中的句子成分，在口语或非正式文体中常省略。例如：
He said（that）you were a good girl．他说你是一个好女孩。
I hope（that）he will come tomorrow．我希望他明天能来。
当that引导几个并列关系的宾语从句时，最后一个that不可省略。例如：
Yang Ming said（that）the book was very interesting and that he enjoyed it very much．杨明说那本书很有趣他非常喜欢看。
②表示一般疑问意义的宾语从句由从属连词if或whether引导。引导词在从句中不担任从句中的句子成分。如果强调“究竟……还是……”时，只能在whether后加not。例如：She wants to know if her uncle likes the new shirt．
I don't know whether this coat is yours or not．我不知道这件外套究竟是不是你的。
③表示特殊疑问意义的宾语从句由连接代词who，whom，whose， what，which或连接副词when，where，how，why引导。引导词在从句中担任从句中的某个成分。宾语从句的语序要用陈述语序。例如：
The small children don't know who Father Christmas is．
—We never know what he is．
—They say he is a doctor．
I asked him which one he liked best．
Could you tell me why you were late for the meeting this morning？
（2）宾语从句的语序
①宾语从句中，从句部分要用陈述语序。特别要注意的是，将疑问句变为宾语从句时，要将从句中的情态动词、连系动词be、助动词will，have，be等移至主语之后，将宾语从句部分变为陈述语序。例如：
Have you decided when you will leave Canada？
Excuse me，sir．Could you tell me where I can find the toilet，please？
Do you know what the population of Chongqing is？
②如果疑问句中的助动词是do，does，did，变为宾语从句时，要将助动词do，does，did去掉，将从句中的动词变为其相应的时态。例如：
I don't know where Mr．Brown lives．
He didn't tell me which floor he livedon．
（3）宾语从句中的时态呼应
①若主句是一般现在时或一般将来时，可根据句子意义使用所需要的各种时态。
例如：Nobody knows where he lives．
Can you see what he's reading？
Do you still remember what he said？
—When will you fly to Sydney？
—Pardon？
—I ask you when you will fly to Sydney．
②如主句是一般过去时，宾语从句的动词要用过去的某种时态。例如：
He asked me where I had been during the winter holidays．
Did you hear what he said clearly？
He wanted to know why she got up late．
③如果主句叙述的是自然现象、客观真理，其从句的时态不受主句的限制，要用一般现在时。例如：
Could you tell me where she lives now？
Could you tell me how far it is from your house to the factory？
The teacher said the earth goes around the sun．
（4）宾语从句中的否定转移问题
在宾语从句中，主句的谓语动词是think，believe等词时、主句的主语是第一人称时，从句的否定要转移到主句上去。例如：
We don't think he will come．我们认为他不会来了。
I don't think you'll like it，will you？我想你不喜欢它，对吗？
（5）宾语从句转化为简单句
①宾语从句可转化为不定式或“疑问词＋不定式”结构，变为简单句。例如：
I don't know when we shall leave for Nanjing．（改为简单句）
→I don't know when _________ _________ for Nanjing．（答案：to；leave）
I don't know how I can keep my room clean．（改写句子）
→I don't know how _________ _________ my room clean．（答案：to；keep）
②宾语从句可以转化为复合宾语结构，变为简单句。例如：
We found that he was a clever boy．（改写句子）
→We found _________ very _________ ．（答案：him；clever）
Tom's mother saw that he was sitting on some eggs．（改写句子）
→Tom's mother saw _________ _________ on some eggs．（答案：him；sitting）
（6）宾语从句的复合结构
在有些动词find，make，think后跟复合宾语时，为了避免句子结构复杂混乱，常用it作形式宾语，而将that从句放在宾语补足语之后，其结构是：“动词（find，make，think等）＋it＋宾语补足语＋that从句”。例如：
We think it important that we learn a foreign language well．我们认为学好一门外语是非常重要的。
