可用作代词、连词、关系代词等，有时可以 省略。但在以下几种情况下that不可省略， 使用时尤其需注意。 一、that用作指示代词，指上文提到的 人或事物(单数名词)，且需一个后置定语来 修饰，此时that不可省 Their cotton output of 1997 w
as double than that of1 987. Mary’s handwriting is far better than that of Peter .
1. that用作普通副词。 I was that/so angry I could have hit him.
? 1。在so...that, such。。。that, in order
They started so early that they might arrive in time. It is such a heavy box that nobody can move it. He worked hard in order that he might catch up with the others.
? Supposing that you were in my position,
what would you do? On condition that you were lost in the desert, you should ask for help as soon as possible
? . now that，意为“既然、由于”。
? Now that they have taken matters into
their hands, the pace of events has quickened.
主句谓语动词之前时，that不可省。 That he came late made his teacher angry. That she was chosen made us very happy. 如用it作形式主语，把从句置于谓语动词 之后时，that可以省略。例如： It is a pity (that) he has made such a mistake. It is obvious (that) he is right.
从句时，that不可省。 The news that our team has won the match is true. My idea is that we should get more comrades to do the work.
谓语动词是及物动词make, find, see等时，且 后有宾语补足语时，that引导的从句可置于宾语 补足语之后，用it作形式宾语，此时that不可省。 We find it necessary that he will succeed. He made it clear that he was not interested in this subject.
当它作为从句的主语时，that不可省。 All that have to do is to practise every day. That’s the same man that asked me for money yesterday. 但如that作从句的宾语时，that可省略。 The letter (that) I received was from my father.
? 四、在强调句型 It is was...that结构中，
that不可省。 It is English that Professor Li teaches us. It was in Shanghai that I saw the film.
系副词。在表明方式、时间或地点的单词后 面，常用that来代替in which，when或where, that也可省去。 ? 一、表示方式时，that (=in + which)常省去。 此时不能用how引导定语从句，但可以把the way去掉之后，直接用how引导。 ? 如：I don’t like the way (in which/that/省 略) these parents treat their children我不 喜欢这些家长对待孩子的方式。
? I don’t like (the way) how these parents
treat their children. 我不喜欢这些家长对待 孩子的方式。
? 二、表示地点时，that (=where=介词+which)
也可省掉。 ? 如： ? Do you know anywhere (that ) I can put up for the night? ? This is the place (that=where=at which) he works
? 三、表示时间时，that (=when=介词+which)
? 如：This is the last time that I shall give
you a lesson. ? We left the day (that/when) he arrived. 我 们在他来的那天走的。
关系副词why，表示原因。 ? The reason that (=why) he lost his life was lack of medical care.
? 在下面这个句子中，不能用why, 只能用
which/that： ? I don’t want to hear any reason( that/which) you might give. 我 不想听你所提出的任何理由。
? 五、the same…as…与the same…that…，
? ? ?
such…as…与such…that… 1、the same…as…引导的定语从句往往侧重方 式，“如同……一样的”， the same…that…引导的定语从句往往侧重同 一对象或人。 如：I bought the same dictionary as you borrowed. 我买了一本和你借的词典一样的词典。 I met the same person that I saw yesterday. 我遇见了昨天我看见的同一个人。 在表示方式时必须用the same…as…。如： You should watch carefully and do the same thing as I do.
导结果状语从句。 ? 如：They had such a fierce dog that no one dare to go near their house. 他们家有 一条凶狗，没人敢靠近他家。 （that在句中 不做成分）
? They had such a fierce dog as I had
never seen. 他们家有一条我从未见过的凶 狗。（as在句中作seen的宾语）