Question

定语从句的关系代词在什么情况下可以省略，请详细解释！

Answer 1

关系代词，在限制性定语从句中做从句中的宾语成分的时候是可以省略的。在非限制性定语从句绝对不能省略。

1、that在定语从句中作表语时。

2、that在从句中作补语时。

3、作状语时的省略。当先行词是reason，且在定语从句中作原因状语时，可以用关系副词why或关系代词that，也可以省略。

语法注意

常用that 不用which的情况：

先行词为不定代词all，little，few，much，anything，everything， nothing， something等时。

先行词被序数词、形容词最高级或the only， the very等所修饰或其本身就是序数词﹑形容词最高级时。

He was the only person that joined the army in his village that year。

以上内容参考：百度百科-关系代词

Answer 2

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。
That is the headmaster with whom my father was talking 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。
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。
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。
This is the best dictionary (that) there is in the library.
4. 状语的省略
（1）当先行词是reason，而且定语从句中作原因状语时，关系代词可用why,that,也可以省略。
That is the reason (why) I did it.
（2）当先行词是way,且在定语从句中作方式状语时，关系代词可用in which,that,也可以省略。
I don't know the way that/ which leads to the top of the mountains.
(3)当先行词是time时，关系代词可用when,that 或省略。
I don't know the exact time (when/that) the sports meet will take place.
注意：关系代词作宾语有时也不能省略。

请采纳，谢谢！

Answer 3

关系代词，在限制性定语从句中做从句中的宾语成分的时候是可以省略的。在非限制性定语从句绝对不能省略。
例如：The girl （who is ）standing there is my sister。括号里的可以省略，standing there 就做一个后置定语。
但也有几种特殊情况，关系代词不用作宾语也可以省略，同学们学习和使用时请注意。
　　在下列情况下,引导宾语从句的关联词可以省略。
　　一、that在定语从句中作表语时。例如:
　　She is all (that) a teacher should be. 她具备一个老师应该具备的所有条件。
　　二、that在从句中作补语时。例如:
　　I'm not the fool(that) you thought me. 我不是你以前所认为的那个傻子了。
　　He is the nicest teacher (that) the students consider him in their school. 他就是学生认为学校中最好的那个老师。
　　三、作状语时的省略。
　　1. 当先行词是reason,且在定语从句中作原因状语时,可以用关系副词why或关系代词that,也可以省略。例如:
　　The reason (why/that) he failed was his laziness. 他失败的原因是因为他懒惰。
　　That is the reason I did it. 那就是我做那件事的原因。
　　2. 当先行词是way,且在定语从句中作方式状语时,关联词可用in which或that,也可以省略。例如:
　　The way(in which/ that) these comrades look at problems is wrong.这些同志看待问题的方式是错误的。
　　That was the way(in which / that) she worked the problem out. 她就是用那种办法解决问题的。
　　3. 当先行词是time时,关联词可用when, that或省略。例如:
　　The second time (that) I saw him was in 2000. 我第二次见到他是在2000年。
　　I don't know the exact time (when/ that) the sports meeting will take place. 我不知道运动会举办的确切时间。
　　4.当先行词是place时,关联词可用where,that或省略。例如:
　　The place(where/ that) we will have our picnic is not decided yet. 我们举行野餐的地点还没定下来。
　　This is the right place he was born.这儿就是他的出生地。(注意:句末不可用介词in)
　　同学们往往认为关系代词作宾语时就一定可以省略,其实不然.在下列四种情况下,关系代词虽作宾语,却不能省略。
　　一、在介词+whom /which结构中, whom, which不能省略。例如:
　　Do you know any shops nearby in which I can buy flowers?你知道附近有可以买到花的商店吗?
　　That is the headmaster with whom my father was talking just now.刚才和我爸爸交谈的那个人是校长。
　　二、在非限制性定语从句中,作宾语的关系代词也不能省略。例如:
　　Mr Green, whom you know, is the tallest in our school. 格林先生是我们学校里最高的,你也认识他。
　　The elephant is like a spear, as anyone can see. 大象像长矛,任何人都知道。
　　三、在the same ... as, such ... as, as ... as, the same... that结构中, as, that 即使作宾语,也不能省略。例如:
　　I have bought the same bike as you (have). (指同类用as)我买了一辆和你的一样的自行车。
　　This is the same book that I read the day before yesterday. 这就是我前天读过的那本书。(关系代词that如要换成as, 则指与我读的书一样,而不是同一本。)
　　四、当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,关系代词第一个可省略,第二、第三个等不可省略。例如:
　　This is the book (which) I read yesterday and which I found very interesting. 这就是我昨天读的那本书,它很有趣。
　　You have many people around you (whom) you always turn to and whom you will never forget.你身边有很多人,你经常向他们求助,你永远不要忘记他们。