只有在先行詞為人和物,人或物得時候才能用that修飾,在that作主語的時候不能省略,在作賓語的時候可以省略.
1）被修飾的先行詞為不定代詞,如all,much,everything,anything,nothing,none,the one,something等時,只能用that.如：
Is there anything that I can do for you?
2）先行詞被only,very,just,last,one of,all,no,little,few,any等詞修飾時,只能用that.如：
The only thing that I want to do is to have a rest.
3）先行詞是序數(shù)詞或被序數(shù)詞修飾時,只用that.如：
He was the first person that passed the exam.
4）先行詞是最高級或被最高級修飾時,只用that
This is the best way that can solve the problem.
5）先行詞既有人也有物時,只用that.如：
The film star and her film that you have just talked about are really very famous.
6）被修飾詞為數(shù)詞時,只用that.如：
He brought two cats yesterday.Now I can see the two that are playing in the garden.
7）如果兩個從句,其中一個關(guān)系代詞用which引導,則另一個用that以避名重復.如：
He built up a factory which produced things that had never been seen before.
8）主句是there be結(jié)構(gòu),修飾其主語的定語從句用that.如：
There is a book on the desk that belongs to Frank.