定语从句难题
(一)关系代词that和which 使用时应注意的几点
1.在下列情况下只用that，不用which
① 先行词是all, everything, nothing, anything, little, much, the one等不定代词时
There is nothing ( that ) I can do.
I mean the one that was brought yesterday.
② 先行词被all, any, every, no, some, little, much等词修饰时
I have read all the books (that) you gave me.
You may take home any of these books that you like.
③ 先行词被序数词或形容词最高级修饰时
This is the first composition (that)he has written in English.
This is the best novel (that) I have ever read.
④先行词被the only, the very(正是,恰是), the same, the last修饰时
The white flower is the only one ( that) I really like.
This is the very book (that) I want to find.
The last place( that) we visited was the hospital.
This is the same watch that I lost yesterday.
⑤ 当先行词有两个或两个以上时,既有人又有物,定语从句用that 引导 (that既可指人也可指物)
He talked about the teachers and schools that he had visited.
2.下列情况不能使用that,而用which
① that 不能引导非限制性定语从句
Football, which is a very interesting game, is played all over the world.
② that不能置于介词之后(介词后指物用which,指人用whom)
The person to whom I am speaking just now is our English teacher.
The prize for which he worked so hard was a new bicycle.
(二)as 做关系代词的用法
1.关系代词常出现在the same…as, such…as, so…as, as…as 等结构中
This is not such a book as I expected.
I live in the same building as he (lives in).
Here is so big a stone as no man can lift.
As many children as came here were my father’s pupils.
★ the same…that…和the same…as…的区别
I have bought the same watch as you have.
我买了一块和你一样的手表。(我的手表和你的手表很像，但不是同一块。)
This is the same watch that I lost. 这就是我丢的那块手表。(这手表和我丢的手表是同一块)
2.as引导非限制性定语从句，指代逗号前的整个句子(即先行词)，可置于句首或句末。
This elephant is like a snake, as anybody can see.
Mary was late for school, as often happened.
As is known to all, the earth is round.
★ as 指代一句话和which 指代一句话的用法区别
as 的这种用法通常出现在一些固定短语之中如：
1.as has been said before 如上所述
2.as may be imagined正如可以想象出来的那样
3.as is well known 众所周知
4.as was expected正如预料的那样
5.as has been already pointed out正如已经指出的那样
6.as we all can see 正如我们都会看到的那样
which则不需要，例如：
The man died last night, which is a lie.
as 替代一句话即可放句首也可放句末，而which只能放句末。
(三)定语从句中的主谓一致
引导词在定语从句中作主语时，其谓语动词人称和数要根据引导词所指内容而定。例如：
1. Here are such sentences as are often used by the students. ( as指代sentences，谓语动词用are)。
2. I, who am a Party member, should work hard for our country.( who指代I, 谓语用am.)。
3. He was one of the students who were praised for it. ( who指代the students) 他是被表扬的学生之一。
4. He was the only one of the students who was praised for it. ( who 指the only one)他是唯一被表扬的学生。
(四)易与定语从句混淆的其他复合句
1.定语从句与同位语从句
定语从句与前面的名词是修饰与被修饰的关系“。。。的(名词)”。而同位语从句是用来说明前面名词的内容。与that从句同位的名词必须是一些表事实或概念的抽象名词，如fact, news, belief, truth, reply等。that在定语从句中作成分，可用which 或who/whom代替;而that在同位语从句中不充当任何句子成分，只起连接作用。试比较：
① We all have heard the news that our team won. (同位语从句，that从句表示news的内容，that 在从句中不作任何成分)
② We don’t believe the news that/which he told us yesterday.
(定语从句，that 作told 的'宾语)
2.定语从句与状语从句。试比较：
① He left the key where he had been an hour before.
(where引导地点状语从句，相当于in the place where)
② He left the place where he lived for many years.
(where 引导定语从句，修饰the place)
③ He is such a good teacher as all of us love and respect.
(as 引导定语从句)
④ He is such a good teacher that we all like him.
(that引导结果状语从句,such…that… “如此…以致…”
3.定语从句与主语从句。试比较：
① As is known to us all, paper was first made in China.
(as 引导定语从句，指代整个主句内容，可置于句首)
② It is known to us all that paper was first made in China.
(it 做形式主语，代替that 引导的主语从句)
4.定语从句与强调结构。试比较：
① It is the house where I met the young man.
(where 引导定语从句，修饰house，where在定语从句中作地点状语)
② It was in the house that I met the young man.
(本句为强调结构，可还原为I met the young man in the house.)
下面咱们一起来分析几道定语从句的难题。
例1.It is the young man _______ looked for _______ caught the murderer.
A. that …who B. that …they C . they …that D they…which
分析：答案是C。本题考查了定语从句和强调句式。强调句式的结构是
“It is + 强调部分 + that/who….”。they looked for前省略了关系代词 that,因为先行词the young man 在从句中做looked for的宾语。强调句为It is the young man who/that caught the murderer.本句意思是“是那个他们寻找的年轻人抓住了杀人犯”。
例2.Is this factory _______ we visited last year?
A. where B in which C the one D at which
分析：做这题首先要明白一个概念。被定语从句修饰的名词前一般都有the，因为它已被限定。所以此题还原成陈述句应该是this factory is______ we visited last year. 而不是this is factory ______ we visited last year.知道这一点后做题容易了，不能选A, B, D。因为句子没有先行词。所以答案是C。从句前省略了关系代词that/which。题目如改为Is this the factory ________we visited last year? 空格处应该用which 或 that。
例3.The book, the cover _______ is broken, is not mine.
A. of it B for C whose D of which
分析：答案是D。先行词the book 代入从句应该是 the cover of the book is broken.相当于whose cover。
例4.This is Mr.Smith, _____ I think has something interesting to tell you.
A who B whom C that D x
分析：此题同学们容易错选B，认为先行词Mr. Smith做think 的宾语。I think, you think, do you think 等表明某人观点的短语是插入语。插入语的特点是去掉不影响句子表达。所以做题时遇到插入语，先去掉，This is Mr. Smith, _______ has something interesting to tell you。很容易得到答案A.
例5.Who _______ has seen the TV film doesn’t admire it?
A that B who C which D as
分析：先行词是who，到是指人，可为了避免重复，不用who，而用能指代人的that。答案是A。
例6.You can never imagine what great trouble I have had ________ the patient who Received a serious wound.
A. treat B. to treat C treating D treated
分析：迷惑的答案是D，同学们容易根据had确定用过去分词。而做好这题，
关键是知道句型have trouble(difficult) doing sth 做某事有困难。定语从句部分是I have had (great trouble)treating the patient.而patient 后又有一个定语从句。答案是C。
例7.This is the last time _________ I shall give you a lesson.
A. when B that C which D in which
分析：答案是B。这里的time不指时间，而是次数。所以用that引导。
例8.I don’t like the way ________ you laugh at her.
A that B on which C which D as
分析：此题先行词是the way，用...方式的短语是in this way。所以定语从句应该是in which you laugh at her。但习惯上也可说that you laugh at her。或者什么也不用you laugh at her。答案是 A。
