1 .由连接代词或副词及whether ( if )引起的从句：
I'll see what I can do .我来想想我能做什么。
I don't knoww who you are .我不知道你是谁。
Could you tell me where you re from? 你能否告诉我你是哪儿人?
I wonde whether ( if )you could help us .不知你可否帮助我们。
2 .由关系代词型的what 及whatever 等词引起的从句：
I'll do what you asked me to .我将按你的话去做。
We'11 give you whatever help you need . 我们将予你需要的任何帮助。
You can read whichever book she recommends . 你可以看她推荐的任何书。
You can ask whomever you trust to help you . 你可以请任何你能信任的人帮助你。
3 .由that 引起的从句(有时that 可省略):
It proved that the world was round .这证明地球是圆的。
I see ( that )you have a lot of experience .我看得出你很有经验。
That doesn't mean I'll win .这并不意味着我会获胜。
I think he live on Mandison street .我想她住在梅迪逊街。
第二类从句常可用作介词宾语(a ) ，第一类从句有时也可用作介词宾语(b ) :
a . This reminded me of what he had once told us .
She was never satisfied with what she had achieved .
b . She was curious as to what he would say next .
He said nothing about who was to be sent there .
I put it to you whether that is the best solution to the problem . 我提出给你考虑这是否是解决问题的最好办法。