7．在以who引导的疑问句后，为了避免重复，只能用that。

Who is the girl that is standing there? 站在那边的那个女孩是谁？

6．先行词是the one时，只能用that。

This is the one that you want.　这就是你想要的。

5．先行词同时含有“人”和“物”的名词时，只能用that。

I can remember the people and some pictures that I saw in the room.我能记得我在房间里看到的人和一些图画。

4．先行词是everything, something, anything, all, none, much, little, many, few等不定代词时，只能用that。

Finally, the thief handed in everything that he had stolen.最后小偷交出了他所偷的东西。

3. 先行词前有all, any, no, little, much, many, the only, the very, the last等修饰词时只能用that。

Here are all the books that I have.　这就是我所有的书。

This is the only book that I like.这是我唯一喜欢的一本书。

2．先行词被序数词修饰时只能用that。

The first English novel that I read was Thirty-nine Steps.我读的第一本英文小说是《39级台阶》。

1．先行词被形容词最高级修饰时只能用that。

This is the most beautiful mountain that I have seen. 这是我所见过的最美丽的山。

2．先行词本身是that时，只能用which，不能用that。

The clock is that which tells the time.钟表是用来报时的。

1．在介词后只用which，不能用that。

This is the bank in which the robbery happened.这是那所发生抢劫案的银行。

4．whose指人或物，在定语从句中作定语。

The girl whose bag is new is called Ann.新书包的那个女孩叫Ann。(指人)

He lives in a house whose widows open to the south.他住在窗户朝南的那所房子。(指物)