that在从句中作主语或宾语,既可以指人又可以指物；which在从句中作主语或是宾语,只能指物
、that与which的区分
1.指物时宜用 that 的情况：
>①、 当先行词为 all,none,much,little,few,something,anything,everything,nothing 等不定代词时.
All that can be done has been done.
>②、当先行词既指人又指物时.He spoke of the men and the thing (that) he had seen abroad.
>③、当先行词是疑问词 who,what,which 时或者句子以疑问词 who ,what ,which 打头时.
Who that has such a home doesn’t love it?
>④、先行词是序数词、形容词最高级 或者 当先行词被序数词或形容词的最高级修饰时.
This is one of the best films that I have ever seen.
This is the best that can be done now.
>⑤、 当先行词被 the very,the only,the last,the same ,just,one of ,any,every ,few ,little ,no ,all ,one of 等修饰时.
This is one of the very book that I am looking for.
>⑥、关系代词在从句中作表语.Mary is no longer the girl that she used to be.
2.只能用 which 不能用 that 的情况.
>①、 引导非限定性定语从句修饰某物或整个句子.
Bruce went towards the fire,which was still smoking.
Tom came back late,which made his parents very angry.
>② 、关系代词作介词的宾语.This is the house in which Lu Xun once lived.
>③、 that,those作主语时Those which are on the desk are English books.
④.先行词是专有名词、整个句子或世界上独一无二的物质名词时,一般用非限定性定语从句修饰.
The sun,which gives us light and heat,is very big.
注意 当引导定语从句的关系代词在从句中作主语时,那么定语从句中的谓语动词的数的形式应与先行词保持一致.