Question

主语从句引导词 “what、which、 that”的区别有哪些？

Answer 1

1. 关系代词作介词宾语,即 介词+关系代词,指物只能用which

2. 非限制定语从句中,指物只能用which,亦可指整个前面的句子.

3. what 一般指代主语

1. That引导主语从句
   That they were in truth sisters was clear from the facial resemblance between them.
   释义：很明显，她们确是亲姐妹，她们的脸型很相似。
   How strange it is that the children are so quiet!

   释义：孩子们这么安静真奇怪！

2. what引导主语从句
   what可以在从句中充当主语和宾语：
   What she did is not yet known.

   释义：她干了什么尚不清楚。
   What makes him disappoint isn’t clear untl now.
   释义：到目前为止，什么事情（东西）使他很失望还不清楚。

3. which 引导主语从句，意思为哪一个，哪一些，一般后面需要紧跟名词，做具体说明是什么东西，是有范围的选择，而what是没有范围。
   which one you choose is right?

   释义：你选择哪一个是正确的？

Answer 2

That引导主语从句
如：That they were in truth sisters was clear from the facial resemblance between them.很明显，她们确是亲姐妹，她们的脸型很相似。
有时that可以放在句首，但当that引导的主语从句出现在疑问句中时，要以it作形式主语，而把主语从句后置。如：Is it true that the scientist will give us a lecture next week?
当主语从句出现在感叹句中时，要以it作形式主语，而把主语从句后置。如：
How strange it is that the children are so quiet! 孩子们这么安静真奇怪！
what引导主语从句
what可以在从句中充当主语和宾语：例如What she did is not yet known. 她干了什么尚不清楚。
What makes him disappoint isn’t clear untl now.到目前为止，什么事情（东西）使他很失望还不清楚。
which 引导主语从句，意思为哪一个，哪一些，一般后面需要紧跟名词，做具体说明是什么东西，是又范围的选择，而what是没有范围。例如which one you choose is right.