(1)that多指物，有时也指人，在定语从句中作主语、表语或宾语，作宾语或表语时可省略。

指物时其用法和which大致相同，但也有区别。

(2)which指物，在定语从句中作主语和宾语，作宾语时，在限制性定语从句中可省略。另外，

which可用来指代前面句子的部分或全部内容。

(3)下列情况只用that不用which：

①先行词是all, something, everything, anything, nothing, little, much, few等不定代词；

②先行词被all, any, every, no, little, much, some等词修饰；

③先行词被序数词、形容词最高级修饰或先行词本身是序数词；

④先行词被the only, the very(正是，恰是)，the last修饰；

⑤先行词中既有人也有物；

⑥在which或who的特殊疑问句中含有定语从句。 This is the book which /that you are looking for.

3) The boy was away from home for a week, which worried his parents very much.

即景活用： 用which, that填空

1) The first place_______________ they visited in Guilin was Elephant Trunk Hill(象鼻山).

2) He talked about the people and the place ____________he had visited in that country.

II. 关系副词引导的定语从句

品味典例：

1) The book has helped me greatly in my daily communication, especially at work where a good impression is a must. (2014·江苏高考单选)

在日常交流中这本书对我帮助很大，尤其是在需要有良好印象的工作之中。

2) I didn't become a serious climber until the fifth grade, when I went up to rescue a kite that was stuck in the branches of a tree.(2014·浙江高考单选)

直到五年级我才成为一个很认真的攀登者，在那时我登高去拿下一个卡在树枝上的风筝。

3) The reason why I don't trust him is that he often tells lies.

1．关系副词when, where, why的先行词是表示时间、地点或原因(一般为reason)的名词，在从句中作状语。有时可用"介词＋which"结构替换。

2．当定语从句中缺少主语或宾语时，即使先行词是表示时间、地点和原因的词仍用which/that。

3．当先行词为一些表示抽象地点的名词，如：point, situation, case, stage等，如果引导词在从句中作状语，常用关系副词where引导定语从句；如果不作状语，则用关系代词that/which。 即景活用：

1) The day will come ______________= (on which) we'll win the final victory.

2) We know the place _________________=(in which) our teacher lives.

3) Do you know the reason____________ = ( for which ) he was so sorry?

4) They have reached the point ____________________they have to separate with each other.