Question

什么时候用what 和that

Answer 1

that引导名词性从句只起连接作用，在从句中不作任何成分，无意义，在宾语从句通常省略，但在主语从句、表语从句和同位语从句中均不能省略；what除引导从句外，还在从句中作成分，意为“所……的(东西)”，在含义上等于“名词+that”。如：
1. 用that的例子
That she lacks experience is obvious. 她缺少经验，这是显然的。
The police learned that he wasn’t there at that time. 警察获知他那时不在场。
He realized that she too was exhausted. 他意识到她也精疲力尽。
My idea is that you shouldn’t have left the country. 我的意见是你不应该离开那个国家。
Bob has the mistaken idea that tomorrow is a holiday. 鲍勃错误地认为明天是一个假日。
It was quite plain that he didn’t want to come. 很明显他不想来。
It is natural that they should have different views. 他们看法不同是很自然的。

2. 用what的例子
What (=The thing that) he said was true. 他所讲的是事实。
What he had hoped at last came true. 他希望的事终于成为现实。
What he said is beneath contempt. 他说的话不值一理。
What he says is true, possibly. 或许他说的是对的。
What she saw gave her a fright. 她看到的情况吓了她一跳。
What I want to say is this. 我想说的是这一点。
I’m sorry for what I said. 我为我说的话表示歉意。
That’s what I want to know. 这是我想知道的。
You had better hear what I have to say. 你最好听听我的意见。
I managed to get what I wanted. 我设法得到了我要的东西。
It was what he meant rather than what he said. 这是他的原意而不是他的原话。
There’s something in what he says. 他的话有些道理。
Her interest was roused by what he said. 他的话引起了她的兴趣。
He was always conscious of the fact that she did not approve of what he was doing. 他一向清楚她不太赞成他的做法。
注：that 可引导同位语从句，what不能。如:
Have you any idea what time it starts? 你知道什么时候开始吗?

Answer 2

what
1.引导名词性从句：I don't understand what he is talking about.
(此句中what在名词性从句里做宾语）
It is difficult to decide what should be done first.
(此句中what在名词性从句里做主语）
2.引导感叹句：I can't believe what a beautiful girl she is.
that
that在定语从句中做主语、表语或宾语,作宾语时可省略.
必须用that的情况：
先行词有人又有物
先行词有形容词最高级修饰
先行词是不定代词
先行词有不定代词修饰
以who,which开头的问句
先行词有the very,the same ,the last等词修饰
先行词有序数词,数词修饰时.
关系词在定语从句中做表语时
不能用that的情况：
介词+关系词
非限定性定语从句
举例：
Is this the book that you borrowed in the library?
这是你在图书馆借的那本书吗?
Who that break the window should be punished．
谁打碎了窗户都要受到惩罚．
All that is needed is a supply of oil.
所需的只是供油问题.
Finally,the thief handed everything that he had stolen to the police.
那贼最终把偷的全部东西交给了警察.

Answer 3

what是一个英文单词，意思是“什么”。属于高频率使用的词汇，多用于疑问句。不过如今以what命名的组织、作品等越来越多。
单词简介
编辑

what[(h)wɔt]

pron. 什么

adv. 到什么程度

adj. 什么, 什么的

n. 本质, 实质, 要素
int. 怎么, 多么
that，英文单词，在英语中使用广泛，可用作形容词、代词、连词、副词，还可用于固定搭配。
词典解释
编辑

代词 pron

1.那;那个,那人,那事,那东西

That's my English teacher.

那边是我的英文老师。

2.(已被提到的)那个,那人,那事,那东西

Who told her that?

那是谁告诉她那件事的?

3.前者

4.(用作关系代词的先行词)那,那个

What is that which you have just stuffed into the plastic cup?

你刚才塞在塑料杯里的是什么东西?

5.(代替句中名词,避免重复)

The output of steel this year has increased by 20% compared with that in 1992.

今年钢产量比一九九二年增长了百分之二十。

6.(用作关系代词,引导关系从句)

形容词 a

1.那,那个

That book isn't mine.

那本书不是我的。

副词 ad

1.【口】那样,那么

Is the problem that easy?

问题有那么简单吗?

连接词 conj

1.(引导名词性从句)

He expressed the hope that we would keep in touch with his firm.

他表示希望我们与他的公司保持联系。

My idea is that we should act on his suggestion.

我的意见是我们应当按照他的建议去办。

That she is still alive is a relief.

她还活着,这是令人感到宽慰的。

2.(引导状语从句,表示原因或理由)因为,由于

We are glad that we have accomplished another arduous task.

我们都感到高兴因为又完成了一项艰巨的任务。

3.(引导状语从句,表示目的或结果)为了,以至于

He is working hard that he can catch up with the class.

他努力用功,以便赶上班上同学。

4.(引导表示愿望,感叹的从句,主句常省略)

ThatI could stay at home today!

今天要是我能呆在家里多好呀!