一、定语从句that不能省略情况
1.非限制性定语从句中,that有其他意思不可省
2.有不定代词时
3.有only时
4.有序数词时
5.指人又指物时
6.有形容词最高级时
二、定语从句中关系词的省略与不省略
1.关系代词which,whom,who,that在定语从句中作宾语时可以省略.
Here is the man (who/that/whom)you're been looking for.
以下情况不能省略:
(1)在介词+whom与介词+which中,whom,which不能省略.
Do you know any shops nearby in which I can buy flowers?
That is the headmaster with whom my father was talking just now.
注:当介词放在*后时,which,whom就可以省略.
Who is the man (whom) you talked with just now?
(2)在非限制性定语从句中,作宾语的关系代词也不能省略.
Mr Green,whom you know,is the tallest in our school.
The elephant is like a spear,as anybody can see.
(3)在the same ...as,such...as,as...as,the same...that中,as,that即使作宾语,也不能省略I have bought the same bicycle as you have (bought).(指同类用as)
This is the same book that I read the day before yesterday.(that指同一个)
(4)当由and,but,or等连词连接两个或两个以上的定语从句修饰一个先行词时,第一个关系代词可省,但第二,第三个不可省略.
This is the book (which) I read yesterday and which I find very interesting.
2.当that在从句中作补语时可以省略.
He is not the man (that) he used to be.
She is all (that) a teacher should be.
3.在there be 结构中出现定语从句,或在定语从句中出现there be 时,用作主语的关系代词也可省略.
There is a man downstairs (who) wants to see you.
This is the best dictionary (that) there is in the library.