每天坚持一点点，每天进步一点点。
前面已经分别讲了where 和 when 引导从句的用法，感兴趣的朋友，请看链接Where 引导的从句-详解-不容错过，When 引导的三类从句，这一讲里，主要介绍what引导从句的用法。
当what 作连接代词，引导名词性从句时，可引导主语从句，表语从句和宾语从句
What 本身在从句中充当主语，宾语或表语。
1． What 表示“所。。。的（事）”的意思， 相当于“the things that..., all that, everything that..等。
例如
a.Leave it with me and I’ll see what I can do. (what 引导宾语从句并作do的宾语)
b.What you have done might do harm to other people. (what 引导主语从句并在从句中作宾语)
2． What 表示“所。。。的（人）”意思，相当于“the person that”等，
例如
a.He is not what he used to be. 他已不是从前的他了。（what 引导表语从句并在从句中作表语）
b.She is no longer what she was five years ago. 她不在是五年前的她了。(what 引导表语从句并在从句中作表语)
3． 引导主语从句
a.What we need is more time. (what 做need 的宾语) 我们所需要的是更多的时间。
b.What really matter is that she wore a pair of white shoes. (what 做matters 的主语) 真正麻烦的是她穿了一双白鞋。
c.What he said at the meeting astonished everybody present.
d.What is most important in life isn’t money.
4． 引导宾语从句
a.People were perhaps more honest a long time ago when life was very different from what it is today. (what 做从句中is的表语) 很久以前当生活与现在的生活完全不同时，人们或许更诚实。
b.People have heard what the Present has said; they are waiting to see what he will do. (what 分别做动词heard 和see 的宾语) 人们已经听到了总统所说的：他们正等着看总统会做什么。
5． 引导表语从句
a.Whether ways will be found to stop pollution or not is just what worries the public. （what 做从句中的主语）是否能找到阻止污染的方法就是所令民众担心的事儿。
b.That is what I want to tell you. （what 做从句中的宾语）那就是我想告诉你的事儿。
c.The little girl is no longer what she used to be. （what 做从句中的表语）这个小女孩不再是过去的样子了。
6． 引导同位语从句
a.They have no idea at all what he is working on. （what 做从句的宾语）他们一点儿都不知道他正在做什么。
b.You have no idea what I suffered. （what 做从句的宾语）你不知道我所遭受的痛苦。
通过以上例句及解释我可以得出：What 常用来引导名词性从句，即主语从句，宾语从句，表语从句和同位语从句what 在引导名词性从句时有两个重要的特点：
1)它在相应的名词性从句中一定有含义，常表示“什么”“所。。。的”“。。。的样子”等
2)它在相应的名词性从句中一定做成分，而且常做主语，宾语，或表语。
What 引导名词性从句的5种用法
a.表示“。。。的东西或事情”相当于 the things that …
1.They have done what they can to help her. 他们已经尽力帮助了她。
2.What Marry is is the secretary. 玛丽的职务是秘书。
3.He saves what he earns. 他赚多少，积蓄多少.
b.表示“。。。的人或的样子”相当于 the person that…
1.He is no longer what he was. 他已经不是以前的那个样子。
2.He is what is generally called a traitor. 他就是人们通常所说的叛徒。
3.Who is it that has made Fred what he is now? 是谁把Fred培养成现在这个样子的？
c.表示“。。。的数量或数目”相当于 the amount/number that …
1.Our income is how double what it was ten years ago. 我们现在的收入是10年前的两倍。
2.The number of the students in our school is ten times what it was before liberation. 现在我校学生的数量是解放前的10倍。
d.表示“。。。的时间”相当于the time that …
1.After what seemed like hours he came out with a bitter smile. 似乎过了几个小时他才苦笑着出来。
2.The young girl was too frightened to speak, standing there for what seemed like hours. 小女孩吓得不敢说话，在那儿站了几个小时。
e.表示“。。。的地方”相当于 the place that…
1.This is what they call Salt Lake City. 这就是他们称为盐湖城的地方。
2.In 1492, Columbus reached what is now called America. 1492年哥伦布到达了现在所称的美洲大陆。
3.What is now the North Sahara Desert was once a civilized world. 现在的撒哈拉沙漠的北部曾经是一个文明世界。
用法说明
1． 这样用的what 相当于“先行词 关系代词”，所以其前不能有先行词：
例句：
你喜欢什么就拿什么吧。
a.You can have what you like. / You can have everything (that) you like. （正）
b.You can have everything what you like. (误)
2． 有时what 可用作限定词，其后修饰一个名词
a.I gave him what books I had. 我把我所有的书都给他了。
b.He gave me what money he had about him. 他把身边带有的钱全给了我。
3． What 后的名词可以是复数名词或不可数名词，但通常不能是单数可数名词：
a.I gave him what book I had. (误)
4． What 后接不可数名词时，有时可有little修饰。注意区别：what 不可数名词= 所有的都， what little 不可数名词= 虽少但全部。
a.I spent what time I had with her. 我所有的时间都是与她一起渡过的。
b.I spent what little time I had with her. 我仅有的一点时间都是与她一起度过的。
That 引导的从句
当that 用作连接次，引导名词性从句时，可引导主语从句，表语从句，宾语从句和同位语从句
在从句中既不充当任何成分，也无实际意义，仅起着连接句子的作用。一般不可以省略（宾语从句除外）。 若从句置于句子后面，代词it作形式主语。
例如
1.It worried her a bit that her hair was turning grey. (that 引导主语从句)
2.It is a fact that the Diaoyu Islands are sacred Chinese territory. （that 引导主语从句）
3.Can you believe (that) in such a rich country there should be so many poor people? (that 引导宾语从句)
4.Tom felt that he knew everybody’s business better than they knew it themselves.
5.We heard the news that our team had won.
6.Another problem is that good soil is gradually lost. (that 引导表语从句)
7.But the truth is that everyone should take care of disabled people, not just the government.
【欢迎大家在下方留言，私信讨论，如有小编写的不到位的，恳请指正。感觉不错请点赞、收藏、转发吧！小编将对每个知识点进行详细地讲解，并有实用的例句。喜欢我，请关注我，和我一起学习，和我一起进步】
,
