宾语从句在复合句中用作宾语的从句叫宾语从句。
掌握宾语从句的三要素：引导词；从句语序；从句时态。
一、引导词。
1、当由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：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.小练习：1. I hear (that) _______________________. （一小时后他会回来）2. He said (that) ______________________. （他非常想念我们）3. The teacher told us (that) ________________________. （地球围着太阳转）2、由一般疑问句充当宾语从句，用if或whether引导，意为“是否”。
I want to know if (whether) he lives there.He asked me whether (if) I could help him.但在下列情况下只能用whether：①与or not连用时，往往用whether。
如：Let me know whether he will come or not．让我知道他是否能来。
②在介词之后用whether。
如：I'm interested in whether he likes English．我关心的是他是否喜欢英语。
We're thinking about whether we can finish the work on time．③与不定式连时，用whether。
如：He hasn't decided whether to visit the old man．他尚未决定是否拜访那位老人。
I don't know whether to go．我不知去否。
He hasn't decided whether to go by bus or by train．他还未决定是乘公共汽车去还是坐火车去。
小练习：1. I want to know __________________________________.（他是否跟我们一起去公园）2. Ask him _____________________. （他是否能来）3. I don’t know ___________________________.（是否要下雨）4. It depends on __________it is going to rain.5. I don’t know _________it is a bird or not.6. Lily asked ________to take some food3、如果宾语从句原来是特殊疑问句，只需用原来的特殊疑问词引导。
Do you know who (whom) they are waiting foe?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.小练习：1. He asked _______________________________.(谁能回答这个问题）2. Do you know_____________________________ ? （哪一个比较小）3. Can you tell me_______________________________ ?（他在哪儿）4. Could you tell me_______________________ ?（我该怎么去车站）填入合适的连词(1) He knew _________he should work hard.(2) She asked _________I was a teacher.(3) I wonder _________my mum is doing now.）(4) My mother asked ______helped me yesterday.(5) ---Can you tell me _______you came last night ?---By bus 二. 宾语从句的语序宾语从句的语序应为陈述句的语序（即主语+谓语）的顺序。
I hear (that) physics i sn’t easy.I think (that) you will like this school soon.Can you tell me how I can get to zoo?Please tell me when we’ll have the meeting.小练习：(1) Can you tell me ____?(A .whom do we have to see B. whom we have to see)(2) The teacher asked the students ____.(A. what they were doing B. what were they doing )(3) She wants to know____.( A. where does he live B. Where he lives )(4) Her father asked _____.(A. who the tallest is B. who is the tallest )(5) Do you know ____?(A. what is on the desk B . what on the desk is )三. 宾语从句的时态1.如果主句的时态是一般现在时或者Could you (please) tell us----?时，宾语从句该用什麽时态就用什麽时态。
即，从句可用所需的任何时态I don’t think (that) you are right.Could you tell me how I can get to the railway station?He says Mary will play with the cat.I think he left yesterday morning.2.如果主句的时态是一般过去时，宾语从句只能用相应的过去时态（一般过去时，过去进行时，过去将来时，过去完成时）。
例如：He asked what time it was.He told me that he was preparing for the sports meet.He asked if you had written to Peter.He said that he would go back to the U.S. soon.He said,“Mary is playing with the cat.”→He said Mary was playing with the cat.He said, “he will go back to China soon.”→He said he would go back to China soon3.如果宾语从句所陈述的是客观真理，其时态常用一般现在时，不受主句时态的限制。
例如：Our teacher said that January is the first month of the year.Scientists have proved that the earth turns around the sun.The teacher said, “the moon moves around the sun.”→ The teacher said that the moon moves around the sun.He said, “light travels much faster than sound.”→He said light travels much faster than sound.小练习：用所给词的适当形式填空(1) He says that he _________ (read) now .(2) Can you tell me if they _________ (finish) the work already ?.(3) Dou you know where John ________(go) yesterday?(4) My sister told me she _________ (be) free tomorrow.(5) I wanted to know if you __________(like) the movie.(6)The teacher told us the earth _________(go) around the sun.(7) Could you tell me if there __________(be) a hospital near here?注意：1、if和when既可以引导宾语从句，也可以引导状语从句，应注意它们在两种从句中的意思和用法的不同。
if和when引导宾语从句时，分别意为“是否”和“何时”，其时态应和主句时态相呼应；它们引导状语从句时，意思分别为“如果，假如”和“当……时候”，当主句时态是一般将来时时，其时态用一般现在时。
它们常常放在含有状语从句和宾语从句的题干中进行综合考查。
如：—Do you know when he will come back tomorrow ？你知道他明天什么时候回来吗？—Sorry，I don't know．When he comes back，I'll tell you．对不起，不知道。
当他回来了，我将告诉你。
—I don't know if he will come．我不知道他是否会来。
—He will come if it doesn't rain．如果不下雨，他会来的。
2、主句的谓语动词是 think, believe, imagine, suppose,等,从句的否定词一般要转移到主句上来,其反义疑问句一般与宾语从句一致.I think he isn’t a student. ×I don’t think he is a student. √I don’t think he is a student. Is he?其他的与主句一致。