在復合句中作主句的賓語，引導詞有：

連詞：that (that ?？墒÷?,whether, if

代詞：who, whose, what ,which

副詞：when ,where, how, why 等,。

(一)that引導的賓語從句(在非正式場合that可以省略)

可跟that從句做賓語的動詞有：

say, think, insist, wish, hope, demand, imagine, wonder, know, suppose, see, believe, agree, admit, deny, expect, explain, order, command, feel, dream, suggest, hear, mean, notice, prefer, request, require, propose, declare, report等。

例句：The boy believes that he will travel through space to other planets.

注意事項：當主句謂語動詞是 think, believe, suppose, expect 等詞,，而賓語從句的意思是否定時,，常把否定轉移至主句表示。

例句：I don’t think it is right for him to treat you like that.

在以下情況中that不能省略

1,、當句中的動詞后接多于兩個由that引導的賓語從句時,，第一個that可省，但后面的that不可省,。

例句：He said (that) you were too young to understand the matter and that he was asked not to tell you.

2,、當主句的謂語動詞與that賓語從句之間有插入語時，that一般不可省,。

例句：Just then I noticed, for the first time, that our master was wearing his fine green coat and his black silk cap.

3,、當that從句是雙賓語中的直接賓語時，that不可省,。

例句：I can’t tell him that his mother died.

注意事項：許多帶復合賓語的句子,，that引導的賓語從句經(jīng)常移到句子后部，而用it作形式賓語,。

例句：I find it necessary that we should do the homework on time.

(二)由whether,if 引導的賓語從句

由whether(if)引導的賓語從句,，實際上是一般疑問句演變而來的。意思是“是否”,。賓語從句要用陳述句語序,。一般說來，在賓語從句中whether與if可以互換使用,，但在特殊情況下if與whether是不能互換的,。

例句：I wonder whether(if) they will come to our party.

只能用whether，不能用if引導的賓語從句

1、在帶to的不定式前

例句：We decided whether to walk there.

2,、在介詞的后面

例句：I’m thinking of whether we should go to see the film.

3,、在動詞后面的賓語從句時

例句：We discussed whether we had a sports meeting next week

4、直接與or not連用時

例句：I can’t say whether or not thet can come on time.

只能用if不能用whether引導的賓語從句

1,、if引導條件狀語從句,，意為“如果”

例句：The students will go on a picnic if it is sunny.

2、if引導否定概念的賓語從句時

例句：He asked if I didn’t come to school yesterday.

3,、引導狀語從句even if(即使)和as if(好象)時

例句：He talks as if he has known all about it.

(三)連接代詞和連接副詞引導的賓語從句

這樣的賓語從句實際上是由特殊疑問句變化而來的,，賓語從句要用陳述句語序。用于這種結構的動詞常常是：see, say, tell, ask, answer, know, decide, show, find out, imagine, suggest, doubt, wonder, discover, understand, inform, advise等,。

英語中的連接代詞有：who,whom,whose,which,what,在句中擔任主語,、賓語、定語或者表語,。

例句：Can you tell me whom you are waiting for?

英語中的連接副詞有：when,where,why,how,，在句中擔任狀語的成分。

例句：None of us knows where these new parts can be bought.