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。
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)
That I could stay at home today! 今天要是我能呆在家里多好呀!
that的用法有：
1、that用作指示代词的意思是“那,那个”。可指前面提到的那件事,也可指在空间或时间上较另一事物远的事物或人,还可指要表明的或要提及的事物、想法等。
2、that用作关系代词时,指人或事物,同时又在从句中充当句子成分。that偶尔也可引导非限制性定语从句。
3、that还常用以代替who, whom, which,但that...which中的that用做关系代词的先行词。
4、that用作连词时可引导主语从句、宾语从句、表语从句、同位语从句和状语从句。
1. 在不定代词,如：anything, nothing, everything, all, much, few, any, little等作先行词时,只用that,不用which.
All that is needed is a supply of oil.
Finally, the thief handed everything that he had stolen to the police.
2.先行词有the only, the very, the just修饰时,只用that.
He is the very man that helped the girl out of the water .
3.先行词为序数词(the last)、数词、形容词最高级时,只用that..
The first English book that I read was “The Prince and the Pauper” by Mark Twin .
4.先行词既有人,又有物时.
He talked about the teachers and schools that he visited .
5.当主句是以who 或which 开始的特殊疑问句时,用that 以避免重复.
Who is the person that is standing at the gate .
6.关系代词在从句中做表语
He is not the man that he used to be .
例如
There are two novels that I want to read. 我要读的有两本小说。
There is no work that can be done now. 没有什么工作现在能做的了。 2.当先行词为主句的表语或者关系代词为从句的表语时。
例如
This is the book that was bought yesterday.这就是昨天买的书。
Our school is no longer the school that it used to be. 我们的学校不再是以前的学校了。 3.以Here is (are)开头的句子时。
例如
Here is a film that will move anyone.这是一部将使任何人受感动的电影。
Here are two books that I will buy.这是我要买的两本书。 4.It is (high)time 定语从句中。
例如
It is time that we should have a rest.我们应该休息了。
It is high time that they started out. 他们该动身了。 5.当先行词是way等词时，关系代词用that或者in which在定语从句中作方式状语时，在口语中，常可省略。
例如
This is the way that my father did this work.这就是我父亲做此工作的方式。
She admired the way in which I answered the questions. 她羡慕我回答问题的方式。 6.在双重限定性定语从句中，如果一个从句用who或者which引导时，那么另一个从句用that引导。
例如
He is the student that I have ever see who can jump highest.他是我曾经看到过跳得最高的学生。
My brother studies in the school which is the most beautiful in our city that isnt far from here. 我的弟弟在我们的城市最美丽的学校读书，并且离这儿不远。 7.当先行词被the last , the very 和the only修饰时。
例如
This is the very pen that I am looking for. 这正是我找的钢笔。
The only book I want to read is missing. 我唯一想看的书不见了。 8.在强调句子中，并且以who ,which, what开头时。
例如
Who was it that was lost ? 究竟是谁迷路了？（此句中，最好不用who来代替that，避免重复。）
What was it that you did last week? 你上周究竟做什么了？9.当先行词有序数词时。
例如
You are the first person that I want to ask for.你是我要见的第一个人。
This is the second book that I have ever written.这是我写的第二本书。 10.当先行词被all, every, no , some, few , little, much, both等修饰时，
例如
This is all that I want to say at the meeting.这就是我在会上要说的。
Have you any books that are worth reading? 你有值的看的书吗？ 11.当先行词既指人又指物时。
例如
The professor and his achievement that I heard about are admired by them .我听说的那位教授和他的成就得到他们的赞美。
Lets talk about the persons and the things that we can remember.让我们谈论能够想起的人和事。 12.当先行词为anything、everything、nothing时，关系代词用that,不用which；但用something时，用which或者that均可。
例如
Everything we have seen in China is moving. 我们在中国看见的东西件件感人。
I have nothing that is worth reading. 我没有什么值得一读的东西。 13.当先行词是疑问代词who时。
例如
Who that you have ever seen can beat him in chess? 你曾见过谁能在棋艺上打败他？以上情况引导词只能用that
以下情况只能用who/which当先行词是that时 当是非限制性定语从句时 当引导词前是介词时 当先行词是指人的不定代词时 只能用that/which。本回答被提问者采纳
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。
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)
That I could stay at home today! 今天要是我能呆在家里多好呀!
形容词
（后接复数名词时用those）。
它用来指已被提到的人或物；也可表对比，指两个中较远的那个。
What about that book you borrowed from me last month？
请注意，that 有时候在句子中具有喜欢或轻蔑等感情色彩。
that little son of his 他那个小宝贝儿子
That George！乔治那家伙！（含有轻蔑语气）
本回答被网友采纳上次我在网上具体看了下。有的。