that在定语从句和在名词性从句中的区别

①从属连词
连接宾语从句的从属连词主要有that,if,whether.that引导表示陈述句的宾语从句,而if和whether引导表示“是否”的宾语从句.
例句：
He told that he would go to the college the next year
他告诉我他下一年上大学.
I don’t know if there will be a bus any more.
我不知道是否还会有公交车.
Nobody knew whether he could pass the exam.
没人知道他是否会通过考试.
②连接代词
连接代词主要有who,whom ,whose ,what ,whoever ,whomever ,whosever,whatever,whichever等.
连接代词一般指疑问,但what,whatever除了指疑问外,也可以指陈述.
例句：
Do you know who has won Red Alert game?
你知道谁赢了这一局红警游戏吗?
I don’t know whom you should depend on.
我不知道你该依靠谁.
The book will show you what the best CEOs know.
这本书会告诉你最好的执行总裁该了解些什么.
Have you determined whichever you should buy,a Motorola or Nokia cell phone?
你决定好是买诺基亚还是摩托罗拉的电话了吗?
③连接副词
连接副词主要有when,where,why,how,whenever,wherever,however等.