㈠ 定語從句中that什麼情況下可以省略
①悶逗派that在定語從句中作賓語或介詞賓語時可省略
He is reading the book (that) he bought yesterday. 他在讀他昨天買的書。
②that作從屬連詞，在句子中沒有實在意義，只起到連接作用，以引導賓螞賀語從句時，也可以省略。
We are sure (that) we can have a better and cleaner place in the future.
我們相信，我們可以有一個更加美好，更清潔的地方。
③so that … 結果狀語從句中的省略
The sound is so weak (that) you cannot hear it. 聲音弱得你聽不見。
(1)定語從句什麼時候可以省略that擴展閱讀
由which, that引導的從句
它們所代替的先行詞是事物的名詞或代詞，在從句中可指型作主語、賓語等，作賓語時可以省略，例如：
1、Prosperity which / that had never been seen before appears in the countryside. 農村出現了前所未有的繁榮。（which / that在從句中作主語）
2、The package (which / that) you are carrying is about to come unwrapped. 你拿那個包裹快要散開了。(which / that在從句中作賓語）
注意： 代表物時多用which，但在下列情況中用that而不用which：
㈡ 定語從句that可以省略的情況
定語從句that可以省略或大的情況具體如下：
1．用作代詞，代替前面所指的事物，常見於表示比較關系的狀語從句中，例如：
It is warmer in the south than(that of)the south.
2．引導名詞性從句作賓語，即賓語從句，例如：
She said(that)she would come.
I suggested(that)we(should)go home.
3．作關系代詞，在定語從句中作表語或賓語，例如：
Can I have the records(that)I lent you?
He is just the man(that)you talked about.
4．在 way（意為manner）後面，that 意思為 in which，例如：
Do it the way(that)I showed you.
5．在表示個人對事物反應、表示重要性或迫切性的adj後所接的從句中，例如：
I am glad(that)you are right.
It is obvious(that)they are happy together.
6．so that, so…that, such…that, 結構中，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．用於表示時間的詞後面，整個短語相當於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．如果定語從句中的謂語是there is，作主衫返豎語的關系代詞that也常省略，例如：
This is the fastest train(that)there is to Beijing.