Question

has everything that can be done been done句子里的that能不能省略，为什么？如果要省略that该怎么改，列

Answer 1

当先行词是 anything, everything, nothing 时，关系代词只能用that。
以下是有关定语从句的详细用法；
（一）
定语从句是用来修饰名词或代词的从句。被修饰的名词叫先行词。从句一般用关系代词或关系副词引导，在先行词之后。关系词在定语从句中充当一个成分。一般来说，关系代词 who （做主语或宾语）和 whom（只能做宾语）指人，which（做主语或宾语）指物，whose 指某人的，that（做主语或宾语，做主语指代人时一般用 who）可指人和物。关系代词充当主语时不能省略，充当宾语时可以省略。where, when, why 是关系副词。where 指地方，when 指时间，why 指原因。
e.g. 1. The man who came to see me this morning is my cousin.
2. He is a student (who, whom, that) we should learn from.
3. The present (which, that) he sent me last night is a nice watch.
4. Fetch me the dictionary which (that) is lying on the desk.
5. Is there anyone whose name is Linda?
6. This is the place where we spent our childhood.
7. He'll always remember the day when his grandmother passed away.
8. This is the reason why they were late for the meeting.
（二）
定语从句可分为限制性定语从句和非限制性定语从句。限制性定语从句用来限制所修饰的对象的意义。这类从句是不能拿掉的。如果拿掉了，那么剩下部分的意思会不清楚。非限制性定语从句只是对所修饰的词作进一步的说明，仅起补充作用，拿掉它，其它部分仍能成立。通常用逗号与它所修饰的对象分开。
e.g. 1. Do you know the teacher who spoke at the parents meeting just now?
2. The book was written by Lu Xun, who was a great writer.
3. They have invited some foreign friends to the Shanghai High School, which is famous both at
home and abroad.
4. Have you ever been to Sydney, which is the most exciting city in Australia?
(三)注意要点：
1． 以下情况不能用关系代词 which (who)，只能用关系代词 that。
1) 当先行词被最高级或序数词修饰时。
This is the best book that I've ever read.
This is the first thing that I want to do.
2） 当先行词是 anything, everything, nothing 时。（something用 which, that都可以。）
He will do everything that he can to help that fatherless child.
3) 当先行词被 all, only, very, any, just, no, much等词修饰时。
I'm not interested in all that he told me.
This is the very book that I've been looking for.
4) 当先行词既指人又指物时。
We talked about the things and persons that we remembered.
5） 当句子中已有 who指人时，关系代词用 that。
Who that has common sense will do such a thing?
6）当关系代词在句子中作表语时。
He is not the man that he used to be.
2. 以下情况不能用关系代词 that。
1) 在非限制性定语从句中，who, whom指人，which指物，不能用关系代词 that。
The boy made the same mistake again and again, which made his teacher rather angry.
2) 在介词后面不能用关系代词 that，指物时用 which，指人时用 whom (不用who)。
The house in which he lives is not far from here.
The man to whom my mother is talking is my teacher.
3. 当先行词是 place（或其它表示地点的词）, time（或其它表示时间的词）, reason时。
1) This is the house where (in which) we lived last year.
This is the museum which we visited last year.
2) October 1 is the day when (on which) the People's Republic of China was founded.
I will never forget the days which I spent with my students.
3) This is the reason why he was late this morning.
This is the reason which (that) may explain his absence.
( why 是关系副词，不能做宾语和主语，只能做状语，表示原因。)
4. 修饰先行词 the way 的三种方法
Can you show me the way in which you make paper flowers?
= Can you show me the way that you make paper flowers?
= Can you show me the way you make paper flowers?
5. whose, of which 使用时的注意点
1) The building whose roof we can see from here is a hotel.
= The building the roof of which we can see from here is a hotel.
2) The book whose cover is green is mine.
= The book the cover of which is green is mine.
6. as 也可引导定语从句，一般用于 such ... as 和 the same ... as 的结构中。另外，也可用于非限制性定语从句中，表示整个句子。
1) I have the same trouble as you have.
2) I feel just the same as you do.
3) Such people as you wrote in the article was well worth learning from.
4) As we had expected, all the students attended the lecture.
(which 也可表示整个句子，但：as“正如；就象”)
7. 一些介词短语不能随意搬动。
The baby (who) my mother is looking after is my nephew.
(错) The baby after whom my mother is looking after is my nephew.
8. 定语从句中谓语的用法。
1) I, who am your best friend, will do everything for you.
2) Tom is one of the boy students in our class who are often late.
3) Tom is the only one of the boy students who is often late.
9. 定语从句中的插入语。
1) He is the teacher, who I think will be our class teacher next year.
2) Jim is the boy, who everybody believes will win the first prize.
(I think, everybody believes, I suppose等插入语，在考虑用什么关系代词、关系副词时，可暂时不予考虑，以免受其迷惑。)
10. 定语从句一定要有先行词。
1) Is this the museum 无 / which / that I visited last week?
2) Is this museum the one I visited last week?
11. 区分非限制性定语从句和并列句。
1) I have two uncles, both of whom are engineers. 非限制性定语从句
2) I have two uncles, and both of them are engineers. 并列句
3) There are two rooms upstairs, neither of which has been cleaned. 非限制性定语从句
4) There are two rooms upstairs, but neither of them has been cleaned. 并列句
12. 区分定语从句和强调句。
1) It was in the street that (where 错) I met my teacher.
2) It was on October 1, 1949 that (when 错) China was founded.
13. 修饰先行词 each time, each day, every time, every day, the first time, the moment, the second 的方法
Each time (不需关系代词或关系副词) I saw him, he was happy.
( 定语从句 / 状语从句 )