英语宾语从句，主语和宾语怎么变？要有例句。

1. 把陈述句变为宾语从句用that引导，that常可省略
   They hope.  She can help them.(变为含有宾语从句的复合句)
   They hope that she can help them.=They hope she can help them.
   2、一般疑问句作宾语从句时用if（是否）或whether引导
   I don't know.  Have they made a plan?   (变为含有宾语从句的复合句)
   I don't know if/whether they have made a plan.    
   注意1：宾语从句的语序必须是陈述句语序
   3、特殊疑问句作宾语从句时用疑问词来引导，此时疑问词变为了连接代词如：what, which, who, whose和连接副词how, when, where, why等。语序要还原为陈述句语序
   ①Jack asked. What was John doing at that time? (变为含有宾语从句的复合句)
   Jack asked what John was doing at that time?
   有时特殊疑问句的语序本身就是陈述的，则不必还原
   ②Mary asked. What was the matter with the radio?  (变为含有宾语从句的复合句)
   Mary asked what was the matter with the radio.   （What 是主语）
   4、感叹句作宾语从句时用感叹词what和how引导, 语序不变
   I said .How big the room is! (变为含有宾语从句的复合句)
   I said how big the room was.=I said what a big room it was.
   注意2：宾语从句的时态通常和主句的时态一致。主句的主语是一般过去时，从句用过去时的某种时态，即：一般过去时、过去进行时、过去将来时、或过去完成时。主句的谓语动词是一般现在时，从句可以是各种时态
   但是当从句是不随时间改变的客观真理时仍用一般现在时
   The teacher told us the earth moves around the sun.

非常齐全的资料，记得采纳哦

在复合句中作主句的宾语，引导词有：
连词：that (that 常可省略),whether, if
代词：who, whose, what ,which
副词：when ,where, how, why 等。
that引导的宾语从句（在非正式场合that可以省略）
可跟that从句做宾语的动词有：
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.
注意事项：当主句谓语动词是 think, believe, suppose, expect 等词，而宾语从句的意思是否定时，常把否定转移至主句表示。
例句：I don’t think it is right for him to treat you like that.
在以下情况中that不能省略
当句中的动词后接多于两个由that引导的宾语从句时，第一个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.
当主句的谓语动词与that宾语从句之间有插入语时，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.
当that从句是双宾语中的直接宾语时，that不可省。
例句：I can’t tell him that his mother died.
注意事项：许多带复合宾语的句子，that引导的宾语从句经常移到句子后部，而用it作形式宾语。
例句：I find it necessary that we should do the homework on time.

例句：宾语从句i think that she is smart.
i 是主语， think是谓语， that及之后是think的宾语。

一主，二宾，三不变
第一人称看主语，
“May I use your knife?” He asked me. →He asked me if he might use my knife.
第二人称看宾语，
“Do you know her telephone number?” He asked me.
　　→He asked me if I know her telephone number.
第三人称不变
Do you know? Where does he live? →Do you know where he lives?