在复合句中充当宾语。
1. that引导宾语从句时无含义,不充当成分,常省略。
  ★that不引导介词的宾语从句,至于except that, in that, save that, but that等是复合从属连词。
     I know(that)you have met him.
     Let's suppose that one day this happens to you.
   在及物动词和宾语从句之间常有间接宾语(指人)。例如:
     I told him(that)he was wrong.
在少数动词如:think, believe, suppose, expect, imagine,calculate, fancy, reckon, be supposed , seem, appear, feel as if, look as if, look like等后面的从句中的否定词经常转移到主句谓语动词上,这叫否定前置/否定转移。
(hope“希望”, guess“认为”后的宾语从句否定不前置。i hope not.“我希望不是那样的”,是i hope so.的否定式。i don’t hope so.是对hope的否定:“我不希望如此”。)
如:I don't think it will be very cold today.
      I don't think you are right.
      I don't believe he has finished his work.
注意
   ①并非必须否定转移。若需要强调从句的否定时就不作转移。
   ②不可把所有可否定转移动词的否定句都理解为否定宾语从句,要根据句意或语境而定。
      I don’t think diplomacy is a field for private enterprise.我不认为外交是私人可以经营的领域。
     We didn’t think we’d be this late.我们没有料到我们会来得这么晚。
   ③当think用在疑问句中,或主句中的谓语动词与状语连用,或主句中的谓语动词被do强调时,不能否定转移。
     Why do you think we can't change your note?
      I do believe tom never tells a lie.
     They still didn’t believe that the food would come.他们仍然不相信洪水会来临。
      I can’t believe that they are married.我不能相信他们已结婚了。
  ④否定转移多用在主句动词为一般现在时的情况。
主句动词为一般过去时、过去完成时、过去进行时、现在完成时、现在完成进行时,或主句动词与情态动词连用,就不能否定转移。此时若主句动词为否定,应考虑是否是对主句动词的否定。
      I had thought that he would not come.
  ⑤当宾语从句中有no, never, hardly, not at all, not a bit, not...enough, can’t help doing等时不能否定转移。
      I think i can't help laughing if i see it.
      I believe he never tells a lie.
▲许多带宾语补足语的句子要用it作形式宾语,而把宾语从句置于句尾。
     We think it wrong that he told a lie to everyone.
     We thought it a pity that she should have missed the chance.
2. whether, if引导宾语从句:表示“是否”可互换,口语中常用if。
     He asked if she would come.
3.连接代词what,who,whose等引导的宾语从句。
     Tell me what you want.
     Do you know who will come at the meeting?
注意 who,whom按照传统语法,从句中who所取代的名词如果是宾语应用宾格whom,但在口语中常用who,
 如:Do you know whom(who)he will invite?
①whose, which, what三个词都带有形容词性质。whose表示所有,意为“谁的”;which意为“哪一个 ”,what意为“什么”。如:
     Whose book it is not important.
     Please tell me which school you want to go.
     He didn't know what time it was.
一般说来,which指的是在一个具体的、较明确的、有限的、较小范围;而what则指较广的或不明确的范围。
 如:Which food,说话人一般指眼前的或明确范围的几种“food”;what food则指许多“food ”,而且说话人心中没有数。
       I don't know which / what food you want.
      如果范围较大或者没有什么范围,最好用“what food”
4.连接副词when,where,why,how引导的宾语从句。
     I don't know when the meeting will be held.
     Please tell me where i can find tom.
     He explained to me why he was absent from the meeting.
     Can you tell me how i can get to the post office?
5.可用whatever, whoever, whomever, whenever, wherever等引导宾语从句。
     Please write down whatever he is saying.
     I don't know whoever will come.
     I'll do whatever you ask me to.
6.表示爱憎情感的动词,如:enjoy, hate, love, like, dislike, don’t mind, resent, appreciate(感激)等以及某些介词结尾的短语动词
如:count on, depend on, rely on, see to, look forward to, be fond of, feel like, see to, 等后,即使没有宾补也要先接形式宾语it,再接宾语从句。
 I like it when she smiles at me.    
 I love it when you sing.
 I hate it if i am spoken to loudly in public.
★★除了but, besides, except, in, save, beyond六个介词后跟that引导的宾语从句外,其他介词都不能。in that是“因为”的意思,其余五个与that搭配都是“除了…”。