宾语从句是名词性从句的一种，相当于名词或名词性短语，在句子中充当宾语。谓语动词、介词、动词不定式、动名词、分词之后均可以带宾语从句。描写情感的形容词（如glad、certain、sure、happy、plead、sorry、afraid等）的后面亦可以带宾语从句。宾语从句同其他从句一样，也应该使用陈述句语序。
一、宾语从句的变法
1.陈述句变宾语从句
陈述句变宾语从句时，语序不变，用that连接（that一般可以省略），此时that无词义，不充当句子成分。
<(1)陈述句：He is an honest man.
宾语从句：My mother always says (that) he is an honest man.
(2)陈述句：They will win.
宾语从句：We believe (that) they will win.
2.一般疑问句变宾语从句
一般疑问句变宾语从句时，语序变为陈述句语序，用if/whether连接（if、whether一般可以互换），其意思是“是否”，也不充当句子成分，句末的标点符号由主句决定。
<(1)一般疑问句：Will they win?
宾语从句：I’m not sure if/whether they will win.
(2)一般疑问句：Does he study hard?
宾语从句：I wonder if/whether he studies hard.广州语言训练学校
3.特殊疑问句变宾语从句
特殊疑问句变宾语从句时，语序变为陈述句语序，用原来的疑问词连接，其意思不变，并且要充当句子成分，句末的标点符号由主句决定。
<(1)特殊疑问句：Who is she?
宾语从句：Could you tell me who she is?
(2)特殊疑问句：What does he want?留学梦
宾语从句：I don’t know what he wants.
如果特殊疑问句的疑问词在句中作主语，变宾语从句时语序不变，原来的疑问词既作宾语从句的引导词，又作宾语从句的主语。lcy
<①What’s the matter with her? Can you tell me?
→Can you tell me what’s the matter with her?
②Who lived here ten years ago? He doesn’t know.
→He doesn’t know who lived here ten years ago.
二、注意事项
1.时态问题。宾语从句的时态原则上应与主句的时态保持一致。
(1)如果主句是现在的时态（包括一般现在时、现在进行时、现在完成时），从句的时态可根据实际情况而定。
<①I don’t know she lives here.
②I am sure he lived here ten years ago.japaneschool13中国
preferred③He believes that he has learned enough.
④I have heard that he will come tomorrow.
(2)如果主句的时态是过去的时态（包括一般过去时、过去进行时），从句的时态应该根据情况使用某一种过去的时态（包括一般过去时、过去进行时、过去完成时）。
<①I knew who lived here.
②My father said that he would buy a new computer next week.who is it
③He said that he had en her.
④She was sorry that she hadn’t finished her homework on time.
(3)当宾语从句表示的是一个普遍真理或客观事实时，即使主句是过去时，从句也要使用一般现在时。
<①My father told me the sun ris in the east.
②He said that his classroom is much bigger than hers.
(4)主句中的would,could不表示过去时态，而是表示一种客气、有礼貌的语气时，宾语从句不用过去时态。
<①We’d like to tell you that you have pasd the exam.
②Could you let me know when he will be back?
2.引导宾语从句的that一般可以省略，特别是在非正式的文本中更是如此。但在某些动词（如answer、imply等）之后，一般需要用that；that也常出现在像assure、inform 等引述动词之后。在较长的句子里，特别是当that引导的从句与动词隔开时，that一般不可以省略。另外，当宾语从句出现并列现象时，第一个宾语从句可以省略that，而第二个宾语从句中的that却不可以省略。
dealer told me how much he was prepared to pay for my car and that I could have the money without delay.
（那个商人告诉我他准备出多少钱买我的汽车，并说我会立即收到钱。）
▲that引导的宾语从句不能放在介词之后。
boasted about his success.=He boasted that he was successful.
（他夸耀他的成功。=他夸耀他成功了。）
▲但在以疑问词开头的名词性从句之前，介词不可以省略。
boasted about how successful he was.
（他夸耀他是多么成功。）
3.if和whether作“是否”理解时的意义完全相同，一般可以互换。但在下列情况下，只能用whether，不能用if。
(1)在正式文体中，句中有or not时
beating<①I wonder whether it is big enough or not.
②We should be on time whether it’s a fine day or not.
(2)引出主语从句、表语从句、同位语从句时
<①Whether it is true (or not) remains a question.(主语从句)
②Whether they can stay with their mother is another matter.(主语从
句)
③The problem is whether he has signed the contract.(表语从句)
(3)作介词的宾语
concerned about whether he has signed the contract (or not).
雅思教材哪个好(4)放在不定式前，与不定式组成词组
hasn’t decided whether to go or not.
(5)作discuss等动词的宾语
discusd whether we should clo the shop.
4.正确区分if和when引导的从句是宾语从句还是状语从句
If和when引导宾语从句时，意思分别为“是否”和“何时”，其中谓语动词的时态一般应和主句谓语动词的时态相呼应；他们引导状语从句时，意思分别为“如果，假如”和
“当……的时候”，若主句中谓语动词的时态是一般将来时，则从句中谓语动词的时态应为一般现在时。
<①We are not sure if it will rain tomorrow.If it rains,our sports meeting will be put of
f.
②When he wake up,he did not know when the train left.
5.在think、believe、suppo、imagine、guess等表示思想和情感变化的动词后的宾语从句有否定转移的情况。
<①I don’t think chickens can swim.
(我认为小鸡不会游泳。)
②I don’t believe she will arrive before 7:00.
(我相信她不会在7点前到达。)
③I don’t suppo you can help us.
科学博物馆英语怎么读(我认为你不会帮助我们。)
6.含宾语从句的反意疑问句
(1）陈述部分是含有宾语从句的主从复合句时，附加疑问部分的主语和谓语的人称和数通常与主句的主语和谓语动词保持对应关系。
< ①He said that he was a good student, didn’t he?
②She never asked me if you could speak English,did she?
(2)陈述部分的主句是I think,I believe等时，附加疑问部分的主、谓语的人称和数什么是同声传译
往往与宾语从句的主、谓语保持对应关系。
< ①I think that she must be our new English teacher, isn’t she?
②I don’t think chickens can swim,can they?
7.宾语从句的简化
（1）hope,agree,decide等动词后的(that)宾语从句中的主语若与主句的主语相同，从句可以简化为动词不定式结构。
hoped that he could pass the English exam.
→He hoped to pass the English exam.
（2）e,watch,hear,find等感官动词后的that宾语从句常简化为“宾语+宾语补足语”结构。其中的宾语为that从句中的主语，宾语补足语为省to不定式或V-ing形式。
heard that the girl sang a song just now.
→Jack heard the girl sing a song just now.
（3）由疑问词引导的宾语从句的主语与主句的主语一致时，宾语从句可简化为“疑问词+动词不定式”结构。
→I don’t know how to do it.
8.宾语从句与形式宾语it
当宾语从句后跟宾语补足语时，通常在宾语从句处使用形式宾语it，而将真正的宾语从句移至句末。
