宾语从句的复合句.
　　概念:复合句也称主从句,即主句和从句,从句须有引导词或叫连词引出,否则复合句不成立.由于连词既起连接主句和从句的作用,表明主从句之间的关系,还在从句中充当一定的成份,有一定的意义,故复合句中的连词常成为考查的焦点.
　　种类分为：
　　1.由that引导的宾语从句.that只有语法作用,没有实在的意义,在口语和非正式文体中可以省略.例如：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.
2.由连接代词who,whom,whose,what,which和连接副词when,where,why,how引导的宾语从句.这些连接代词和连接副词在宾语从句中充当某个成分.例如：
Do you know who (whom) they are waiting for?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.
3.由if或whether引导的宾语从句.If和whether在句中的意思是“是否”.例如：
I want to know if (whether) he lives there.He asked me whether (if) I could help him.
注意一下情况只用whether,不用if
whether引导的从句常可以与连词or或or not直接连用.如：
正：Let me know whether you can come or not.误：Let me know if you can come or not.
当宾语从句提到句首时,只能用whether引导.如：
正：Whether it is true or not,I can’t tell.误：If it is true or not,I can’t tell.
3.whether可以引导带to的不定式.如：
正：I don’t know whether to accept or refuse.误：I don’t know if to accept or refuse.
4.whether及其引导的成分可放于介词之后,作介词的宾语.如：
正：I worry about whether I hurt her feelings.误：I worry about if I hurt her feelings.
不懂还可以再问哦.