一、定语从句的概念：，下面我们就来说一说关于定语从句为什么是完整的?我们一起去了解并探讨一下这个问题吧!
定语从句为什么是完整的
一、定语从句的概念：
在复合句中修某一名词或代词的从句叫定语从句。被定语从句修饰的名词或代词等被称为先行词,一般放在定语从句的前面。特别提示：有时候整个句子作为先行词。
I hope I can continue to study here for a postgraduate degree and work as a doctor，which one day will make me able to repay some of the kindness that China and its people have shown toward me.
二、定语从句的关系词：
1.引导定语句的关系词有关系代词和关系副词,常见的关系代词包括that，
which， who，whom,whose等，在从句中做主语、宾语、表语、定语等，关系副词包括 where，when, why等，在从句中做状语。
2.定语从句的分类：
根据定语从句与先行词的关系,定语句可为为限制性定语从句及非限制性定语从句。
限制性定语从可紧跟先行词,主句与句不用号分开,从句不可省去,非限制性定语从句
主句与从句之间有逗号分开，起补充说明作用，如省去意思仍完整。温馨提示：that 和why 不能引导非限制性定语从句。
3.关系代词的用法：
a. that可以用于指人可以用于指物。在从句中作主语或宾语,作主语时不
可以省略，作宾语也可以省略。例如：
Kate likes music that is quiet and gentle.
The dress that I put on the desk is blue.
b. which用于指物，在句中作主语或宾语，作主语不可省,作宾语可省略。例如：
The province which stands on the river is very beautiful.
The film (which) we saw last night was wonderful.
c.Who,whom 用于指人，who用作主语，whom用作宾语。
The lady who often helps me with my English is from England.
注意：1.当前面有介词时只能用whom/which,不能用who/that。如:
This is the house in which we lived last year.
Please tell me from whom you borrowed the English novel.
2.含有介词的固定动词词组中,介词不可前置,只能放在原来的位置上。例如:
This is the person whom you are looking for.
3.that作介词的宾语时,介词不能放它的前面,只能放在从句中动词的后面。例如:
The city that she lives in is very far away.
重难点：
1.关系词只能用that的情形
a.先行词被序数词或形容词最高级所修配,或本身是序数词、形容词最高级时,只能用that,而不用 which。如：
He was the first person that passed the exam.
b.被修饰的先行词为all, much, little,few,something, everything, anything, none,nothing等不定代词时,只能用that,不能用which。例如:
There is not much that ougt to be done right now.
C.先行词被 the only. the very, the same,the last, little, few等词修饰时只能用that,而不用 which.例如:
This is the same bike that I lost.
d. 先行词里同时含有人和物时，只能用that, 而不用which。例如：
I can remember well the person and some pictures that I saw in the room.
e. which引导的特殊疑问句,为避免重复只能用that,如：
Who is the girl that is crying?
f.主句是there be结构，修饰主语的从句用that, 而不用which。如：
There is a book on the desk that belongs to Tom.
g.先行词在主句中做表语，在从句中也做表语时：
The city is not the one that it was.
2.关系词只能用which,而不用that的情况：
a.先行词为that或those时，用which，而不用that。如：
What's that is under the desk?
b.关系代词前有介词时用which而不用that。如：
This is the room in which he lives.
c.引导非限制性定语从句不用that用which。.如
Tom came back, which made me happy.
d.当有两个定语从句时，其中前一个的关系代词用that,后一个用which。
I often read the story that I bought from the bookstore which is newly open to us.
3.that 和who的用法辨析：
that和who在定语从句中做主语或宾语，先行词都可以指人。当做宾语时，都可以省略。一般情况下，可以通用。但是下面的情况除外：
a.宜用who不用that的情况
先行词是指人的不定代词；先行词是those时：在非限制性定语从句中。
b.宜用that不用who的情况
主句是以who引导的特殊疑问句式。
4.as的用法
as引导限制性定语从句时，先行词前面有so,such , the same ,as修饰时，构成the same/so/such/as...as。其中关系代词as在从句中充当主语、宾语或表语。
We have found such a wonderful place as is used for their factory.
Those phones are sold at suc a low price as people expected.
She is not the same person as she was.
四、关系副词的用法：
- When指时间，其先行词表示时间，在句子中做时间状语。如：
This war was the time when he arrived.
- where指地点,其先行词表示地点,在句中作地点状语。如：
This is the place where he works.
(3)why指原因,其先行词是原因,在句中作原因状语作用。例如:
Nobody knows the reason why he is often late for school.
讨论：
the same ...as....和the same...that...的区别是什么呢？
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