英语定语从句中什么情况下只用that,不用which?又在什么情况下只用which,不用that呢?
3个回答
（1）当关系代词紧跟介词,作介词宾语时,只能用which或whom,不能用that.但当介词位于从句句末时,仍可用that或省略.如：
This is the house about which we wrote to you.
Do you know the man to whom your brother writes?
I have read the book (which /that) you told me about.
（2）当先行词是all, everything, something, nothing等不定代词,或被first, last, only, few, much, some, no, any以及形容词的最高级修饰时,只能用that,不能用which.如：
All (that) they needed were qualified workers.
This is the most difficult book (that) I have ever read.
（3）在非限制性定语从句中,只能用which, who, as,不能用that.非限制性定语从句既可修饰先行词也可修饰整个主句,往往起补充说明的作用,并有逗号与主句隔开.如：
He was ill for a month, which set him back a lot in his work.
I want to buy a house, which has a garden.
有用请采纳,谢谢!
