1关系代词（先行词在从句中充当主语或宾语时）：
that(人或物)，which（物），who(人)， whom(人)（只作宾语），who(指代先行词的所有格，可替代人或物)
2关系副词（先行词在从句中充当状语时）：
where(充当地点)=介词+which; when(充当时间)=介词+which; why(充当原因)=for which
3 who cover=the cover of which=of which the cover
who money=the money of whom=of whom the money(后两种很少用)
巧字开头的成语
4 介词后的关系代词只能用which指代物，用whom指代人
The man to whom you spoke was a scientist.
The city in which she lives is far away.
5 只能用that 做关系代词的情况
猕猴桃酒
1) 先行词为不定代词什么枸杞最好everything，little，much，all，anything，nothing , none 等 。
e.g. Finally, the thief handed everything that he had stolen.
2) 先行词前有形容词最高级时，或是最高级时，用that。
e.g. This is the best book (that) I have ever read.
3) 先行词被the only，the very，the last ，the same ,the just等 修饰时，用that。
e.g. He is the only person that I want to e now.
4) 先行词同时指人和指物时，用that。
e.g. We talked about the things and persons that we saw then.
5) 先行词被序数词或the last 修饰时，
e.g. He was the first person that 教师转正个人总结got to the Mount Emei.
6) 先行词是或被不定代词all, few, little, much, every, some, no等修饰时。
e.g. I have done all that he told us to do. 我已完成了他让我做的一切。
He has no books that I need. 他没有我所需要的书。
7) 当先行词是疑问词who， which, what或主句以这些词开头时，
e.g. which is the star that is never to the earth?
Who is the girl that is standing under the tree?
6 当tho作为先行词指人时，通常只能用who引导；
7 The earth is round. _It __ is known to all.
The earth is round, _as/which__ is known to all.
__As___ is known to all, the earth is round
__It____ is known to all that the earth is round.
定语从句在句首时只能用as，as是准关系代词
as 具有正如之意，与之搭配的动词一般是固定的，如：
as you know/ as you e/as we planned/as we expected
8 当先行词有the same 修饰时，关系代词可以用that, 也可以用as,但意思不同
This is the same pen as I lost. 这本书和我丢的那本一模一样。（the same ---as---相似物）
相山公园
This is the same pen that I lost. 这本书就是我丢的那本。（the same---that---同一物）
9 当先行词是the way（方式）时，定语从句用that或in which或省略
I don’t like the way that/in which/省略you talked to your mother.我不喜欢你跟你母亲说话的方式。
10 非限制性定语从句不能用that引导，也不能省略
Teachers who are kind are popular with the students.（限制性定语从句限定前面的名词，不可省略）
Mr. Wang, who is kind, is popular with the students.（非限制性定语从句对前面的名词进行补充解释，省略的话不影响句子）（一些专有名词后通常加非限制性定语从句）
I am reading Harry Porter干蘑菇, _which_ is an interesting book.
区分He failed in the exam. ___It____ made his parents angry.
He failed in the exam, __which_____ made his parents angry.
非限制性定语从句，which可以替代前面的整个句子，如上句。中国灵异
区分He has two sons. Both of __them______ are teachers.
He has two sons, both of ___whom_____ are teachers.
区分The earth is round. _It____ is known to all.
The earth is round, _which/as____ is known to all.
_As____ is known to all, the earth is round（定语从句在句首时只能用as）
_It_____ is known to all that the earth is round.(that从句是主语从句，it作形式主语)
as 具有正如之意，与之搭配的动词一般是固定的，如：
as you know/ as you e/as we planned/as we expected
11 当先行词有the same 修饰时，定语从句可以用that或as引导，但有区别。
This is the same pen as I lost. 这本书和我丢的那本一模一样。
the same---as----(指相似物)
This is the same pen that I lost. 这本书就是我丢的那本。
the same ---that---(指同一物)
12 当先行词有so或such修饰时，定语从句用as引导
This is such an interesting book _as_ we all like.
This is so interesting a book _as_ we all like.
这是大家都喜欢的如此有趣的一本书。(定语从句)
区分：This is such an interesting book _that___ we all like it.
This is so interesting a book __that__ we all like it.
这本书如此有趣，以至于大家都喜欢。(结果状语从句)
13 Is this the factory _which/that/省略__ you visited the other day?
V S P
Is this factory _the one which/that/省略__ some foreign friends visited last Friday?
V S P
Is this the factory _where/in which___ he worked ten years ago?
14 ----的原因是----
The reason why----- is that ----
定从江苏社保查询 表从
The reason why he was late was that he misd the bus.
15 区分
I’ll never forget the days ___when/in which___________ we worked together.
I’ll never forget the days ___that/which //________ we spent together.
I went to the place where I worked ten years ago.
I went to the place _which/that//________ I visited ten years ago.
This is the reason _____why/for which__ he was late.
This is the reason _____that/which//___ he gave.
