一个关于英语语法的问题

我补充下楼上的吧

引导词只能用that的情况
* 先行词既有人又有物时,要用that 而不用which/who引导定语从句. He talked about some writers and books that were unknown to us all.
* who或者which开头的疑问句中,若还要用关系代词引导定语从句时,要用that引导定语从句而不用who和which.Who is the girl that is singing in the hall (避免重复)
* 在there be 句型中,只用that,不用which. There is a park (that) we often visit on Sundays.
* 当先行词在定语从句中充当表语时,关系代词一般只能用that.My hometown is no longer the town (that) it used to be ten years ago.

引导词不能用that 的情况
* 非限制性定语从句中不能用that.
* 介词后不能用that.
* 当关系词后面有插入语时用which引导定语从句而不用that. Here is the English grammar book which, as I have told you, will help to improve your English.
* 先行词本身是that时,一般用which引导定语从句,以避免重复.The predicate is that which is said of the subject.

where在从句中一般做壮语 that可以形容人或物，而which一般只形容物 总之，that和who可以形容人，而that和which形容物 that前一般没有逗号，which前可以逗号分开 从句中做介词宾语时，一般用which，而不用that

This is the room where we held party.

This is the room in which we held party.

This is the room that is the biggest in this building.

This is the room which is the biggest in this building.

This is the room, which is the biggest in this building.

x This is the room, that is the biggest in this building. (不这样用)

x This is the room in that we held party. (不这样用)