㈠ 定语从句中that什么情况下可以省略
①闷逗派that在定语从句中作宾语或介词宾语时可省略
He is reading the book (that) he bought yesterday. 他在读他昨天买的书。
②that作从属连词，在句子中没有实在意义，只起到连接作用，以引导宾蚂贺语从句时，也可以省略。
We are sure (that) we can have a better and cleaner place in the future.
我们相信，我们可以有一个更加美好，更清洁的地方。
③so that … 结果状语从句中的省略
The sound is so weak (that) you cannot hear it. 声音弱得你听不见。
(1)定语从句什么时候可以省略that扩展阅读
由which, that引导的从句
它们所代替的先行词是事物的名词或代词，在从句中可指型作主语、宾语等，作宾语时可以省略，例如：
1、Prosperity which / that had never been seen before appears in the countryside. 农村出现了前所未有的繁荣。（which / that在从句中作主语）
2、The package (which / that) you are carrying is about to come unwrapped. 你拿那个包裹快要散开了。(which / that在从句中作宾语）
注意： 代表物时多用which，但在下列情况中用that而不用which：
㈡ 定语从句that可以省略的情况
定语从句that可以省略或大的情况具体如下：
1．用作代词，代替前面所指的事物，常见于表示比较关系的状语从句中，例如：
It is warmer in the south than(that of)the south.
2．引导名词性从句作宾语，即宾语从句，例如：
She said(that)she would come.
I suggested(that)we(should)go home.
3．作关系代词，在定语从句中作表语或宾语，例如：
Can I have the records(that)I lent you?
He is just the man(that)you talked about.
4．在 way（意为manner）后面，that 意思为 in which，例如：
Do it the way(that)I showed you.
5．在表示个人对事物反应、表示重要性或迫切性的adj后所接的从句中，例如：
I am glad(that)you are right.
It is obvious(that)they are happy together.
6．so that, so…that, such…that, 结构中，例如：
I came to see you so(that)you would know the truth.
She had so many children(that)she didn’t know what to do.
I was having such a nice time(that)I didn’t to leave.
7．用于表示时间的词后面，整个短语相当于when，世吵例如：
I joined the army the year/month(that)my father died.
I thought her nice and honest the first time(that)I met her.
I though her nice and honest when I met her.
8．如果定语从句中的谓语是there is，作主衫返竖语的关系代词that也常省略，例如：
This is the fastest train(that)there is to Beijing.