1、that 作指示代词
如：That is the greatest guarantee of success.
那是成功的最好保证。
2、that 作指示形容词
如："Do you remember that guy you were dating? What happened to him?" she asked.
你记得和你约会的那个小伙吗？他发生什么了？她问。
[注] that 作指示代词和指示形容词的更多用法可以参见《指示代词和指示形容词》一文。
3、that作关系代词引导定语从句
如：This is the sort of thing that Jeremy loves.
这是杰里米喜欢的东西。
4、that 作连词
that 可以作连词引导各种名词性从句，包括宾语从句、主语从句、同位语从句和表语从句。
1) that 作连词引导宾语从句
They have recommended that the site be closed and repaired.
他们建议将该处关闭并进行维修。
2) that 作连词引导主语从句
That you will win the medal seems unlikely.
你想获得奖牌看起来是不可能的。
3) that 作连词引导同位语从句
The idea that modern art can only be seen in museums is mistaken.
现代艺术只能在博物馆才能见到的想法是错误的。
4) that 作连词引导表语从句
One problem is that I don't look any different from other people.
有一个问题是我看起来和其它人没有任何不同。
5、that作副词
that和 this 都可以作副词，用于修饰形容词或修饰另一个副词，表示“这么，那么，如此，这般”的意思，如：
There aren't that many people here.
这儿没这么多人。
6、that的常见句型搭配
that还有很多词组和搭配，尤其需要熟悉下边这些与英语句型有关的结构。
1）so that以便, 以使；以致
如：Read the advertisements so that you can compare prices.
你应该看一些广告以便比较价格。
2）in order that为了
如：I am saving money in order that I can buy a house.
我正在攒钱，以便能买一所房子。
3）except that除了(...之外); 只是
如：Act 2 is similar, except that the orange block is smaller.
第2幕(跟第1幕)类似，除了那个橙色块小了一些。
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。
that名词性从句：
1、引导宾语从句。及物动词后的引导词that可省略。
2、 引导主语从句。通常采用it作形式主语的句型。
3、引导表语从句。 The trouble is that we are short of money.
4、引导同位语从句。引导同位语从句的that和引导定语从句的that是不同的。前者只起语法作用，在从句中不作任何成分；而后者在定语从句中作主语、宾语或表语。
以上内容参考百度百科——that
本回答被网友采纳pron.
1. 那;那个,那人,那事,那东西
That's my English teacher over there.
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)
a.
1. 那,那个
That book isn't mine.
那本书不是我的。
ad.
1. 【口】那样,那么
Is the problem that easy?
问题有那么简单吗?
conj.
1. (引导名词从句)
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)
That I could stay at home today!
今天要是我能呆在家里多好呀!本回答被提问者采纳
the
man
that
he
was
talking
about,,,
the
problem
that
we've
spent
a
lot
of
time
on...
其实the
boys
that....
和the
building
is
extablished
in
New
York
that......个两个句子差不多的
如果我在the
boys后面加个are
playing
football然后再加that的话，那个两个句子就一样的
Mary
has
a
euphonic
voice
that.....
这句也是
这里that后面要引出的是a
euphonic
voice
怎么样
上面个些that还是可以省略的
Most
of
us
don't
believe
that
living
thing
exist
in
outer
space.
most
of
us
don't
believe可以单成个句子，它后面那个that就是引出不相信的内容。
ensure
that……这THAT能省略吗？这得看具体的语境。
Try
to
ensure
that
this
timetable
is
strictly
kept
to.
务必确保严格遵守该时间表。
后面如果接句子，THAT就不能省。
We
must
also
ensure
economic
democracy.
经济民主很值得注意
如果接的不是一个句子而是个词，就不用加THAT。
adv. 那么；那样
conj. 因为；以至于
adj. 那；那个
that is: 换言之；就是说