在复合句中用作宾语的从句叫做宾语从句。它是众多从句中的一员，在复合句中作主句谓语动词、介词或某些形容词的宾语。
在及物动词的后面可以接一个名词来充当宾语，如： I know the man.
而这时也可以用一个句子来充当宾语，如： I know that the man is a policeman.
宾语从句三大块: 1. 引导宾语从句的连词和代词选择; 2. 宾语从句的语序; 3. 宾语从句的时态。
Ⅰ.宾语从句的引导词
1.陈述句充当宾语从句时，用that引导，that无词义，在口语或非正式文体中常省略。如：
My teacher said I was a good boy.老师说我是个好男孩。
She doesn’t know (that) she is seriously ill. I am sure (that) he will succeed.
用以下开头与下列句子连成宾语从句:
1. I know …
2. She says …
3. Tell your friend …
(that)
1.This is a book.
2.You like singing.
3.He worked last night.
4.They will go home.
5.Jim has been to Beijing.
6.She sings well.
2.当由一般疑问句充当宾语从句时，用if或whether引导，意为“是否”。如：
(1) Is Jim a good student? I don’t know
I don’t know if /whether Jim is a good student.
(2) Does Kate get up early? Do you know?
Do you know if /whether Kate gets up early?
用以下开头与下列句子连成宾语从句:
1.Do you know …
2.I want to know …
3.The teacher asks …
if/whether
1.Is he reading ?
2.Do you get up at six?
3.Does Tom work hard?
4.Did you watch TV ?
5.Will they read books ?
6.Can you sing ?
注意：只能用whether不用if 的三种情况
• 一般情况下，if 和whether可以互换，但以下3种 情况只能用whether：
• ①与or not连用：
He asked me whether or not I was coming. Let me know whether you can come or not.
• ②在介词之后：
It depends on whether it is going to rain. I worry about whether I hurt her feelings
• ③在不定式之前：
We haven’t decided whether to go there. I don’t know whether to accept or refuse.
3.如果宾语从句原来是特殊疑问句，只需用原来的疑问词引导。如：
1.What is she doing? Can you tell me?
Can you tell me what she is doing?
2.Where does she live? Do you know?
Do you know where she lives?
