小学六年级定语从句语法专项讲解
定语从句中的that用法
英语语法顺口溜：
that用法真有趣， 两个地方它不去;
逗号后边它不去， 介词之后不考虑;
That做为关系代词，不可用在非限制性定语从句中，即不可用在逗号后边;定语从句中介词之后也不可使用。在逗号或介词后，指物时用which,指人时用who或whom。
例句1)They arrived at a farmhouse, in front of ______sat a small boy.
A. whom B. who C. which D. that
解析：在介词of之后指物，选择C which。
例句 2)The engineer with _____my father works is about 50 years old.
A. whose B. who C. which D. whom
解析：选择 D whom。介词后指人。
例句 3)The letter is from my sister, ______is working in Beijing.
A. which B. that C. whom D. who
解析：选择 D who。逗号后指人，在定语从句中做主语。
定语从句中的that和which
英语语法顺口溜：
That which代表物，区别听我来叙述;
先行若是不定代，that就把which 踹;
当先行词为anything，everything，nothing，all，any，much，many，one等不定代词时，只能使用“that”, 不用 “which”。
例：Is there anything that I can do for you? 我能给你做点什么吗?
先行词前有两数， 就用that定无误;
当先行词是基数词或序数词修饰时，只能使用“that”，不用 “which”。
例句： That is the second time that I have been to Japan. 那是我去日本的第二次。
The two buildings that lay on the River Thames fell down last week.
坐落在泰晤士河岸边的那两座大楼上星期倒塌了。
先行词前最高级， 还用that必无疑;
当先行词是形容词最高级或被形容词最高级修饰时，只能使用“that”, 不用 “which”。
例句：This is the most wonderful time that I have ever had.
这是我度过的最美好的时光。
句中若有there be, that应把which替;
例：There is no evidence that animals possess a mysterious sixth-sense allowing them to predict natural disasters. 说动物拥有神秘的第六感，可以预知自然灾害，这是没有根据的。
先行主中做表语， 避免重复从句里;
例句：1)This is not the hospital that it used to be.
这已经不再是以前那座医院了。
2)Mr Thomson is not the man that he was.
汤姆森先生已经不再是以前的他了。
解析：定语从句的先行词均在主句中做表语。
例句：Which is the course that we are to take ?
我们要学哪门课?
解析：句中已有which,后面不再用which,避免重复用that。
(Just the only very same last, 其后也要用that;)
先行词前有Just 、the only、 very 、same 、last等词，关系代词用that，不用which。
例句：1) The North Pole is the only place that you can see polar bears.
北极是唯一能见到北极熊的地方。
2)This is the same bike that he lost.
这就是他丢了的那辆自行车。
注意区分：
3) This is the same bike as he lost.
这辆自行车和他丢的那辆一样。(但不是)
定语从句中的 that who, who, Those
英语语法顺口溜：
指人可用that who, 以下情况多用who;
Those people做先行，There be的结构中;
例句：
1) Those who are for the plan, please raise your hands.
赞成计划的人请举手。
2) People who create computer viruses are called hackers.
制造电脑病毒的人被称为黑客。
3) There was once a little boy who came to the net bar to play games every night.
曾经有一个小男孩每天晚上都来网吧玩游戏。
先行指人不定代，从中做主who要在：
先行词是指人的不定代词，如 one 、someone 、anyone 、nobody 等词，或指人的关系代词在定语从句中做主语，要用who, 而不用that。
例句：
1)Nobody who knows a little scientific knowledge will believe you.
懂得一点科学知识的人都不会相信你的话。
解析：nobody是指人的不定代词，用who, 不用that。
2)The thief who pretended to be a manager was caught stealing a car.
那个装扮成经理的贼在偷车时被当场抓获。
解析：who指人，在定语从句中做主语。
两个定从一起来，不要重复你有才：
一个先行词有两个定语从句时，关系代词要避免重复使用。
A plant that can cure diseases, which was known by the ancient Chinese , is called Chinese herbal medicine. 一种能够治病的，被古代中国人所熟知的植物，叫做中药。
定语从句中关系代词whose
英语语法顺口溜：
定从之中少定语，whose为你唱一曲：
Whose指人又指物，所属关系要记住。
Whose也是一个关系代词，在定语从句中做定语，表示人与人、人与物或物与物之间的所属关系，特别要注意，物与物之间的关系也用whose。
例句 1)Is there anyone in your class whose family is in the country?
解析：anyone是先行词，whose=anyone’s，在定语从句中做定语。
例句 2) Pass me the book whose cover is red.
解析：the book是先行词，whose=the book’s, 在定语从句中做定语。
定语从句中的As/which/So /such …that
英语语法顺口溜：
As/which在句末，若有否定as错;
as和 which都可指代前面一句话，请看例句:
1)Alice received an invitation from her boss, which came as a surprise.
爱丽丝受到了她老板的邀请，这使她感到吃惊。
2)The weather turned out to be very good, which was more than we could expect.
天气结果变好了，这是我们没有预料到的。
若有否定as错;
3)The result of the experiment was very good, _______ we hadn't expected.
A. when B. that C. which D. what
【简析】答案是C。由于非限定性定语从句是否定结构，只能用which引导，不能用as来替代which。
句首只能用as,还有认知猜想词;
置于句首时，非限定性定语从句只能用as引导。例如：
As is known to everybody, the moon travels round the earth once every month.
众所周知，月亮每月绕地球一周。
与表示认知猜想的词，如know, expect, see, report, 连用时，要用as。
1)As we know, smoking is harmful to one's health.
我们知道，吸烟对健康有害。
2)As is expected, his daughter entered a key university.
正如人们所期望的那样，他的女儿考入了一所重点大学。
固定结构用as, the same /such/so/as;
1) 在the same …as….结构中。意思是 “像……一样的”。 例如：
Chongqing is not the same city as we have seen in other places.
重庆和我们在其它地方看过的城市不一样。
注意区分: the same ….that….,请看例句：
This is the same pen that I lost. 这正是我所丢的钢笔。(同一)
This is the same pen as I lost. 这支钢笔和我丢的那支一样。(相似，不是一个)
2)在as...as结构中，意思是“像……那样的”。例如：
No period in history has had as many important changes _______ have taken place in the past century. 没有哪个历史阶段像过去的一个世纪这样有如此多的重大变化。
3)在such…as…结构中, 意思是“像……那样的”。例如：
Mathilde had to work hard day and night and bought such a diamond necklace as she had lost to pay back to Jeanne.
马帝尔德不得不日日夜夜地干活，来买一个像被她丢掉的那样的钻石项链还给让。
So /such …that宾不离，so/such…as宾要弃;
在so/such…that结构中，that后引导的不是定语从句，而是状语从句，从句中必须有宾语;在so/such…as结构中， as后引导的是定语从句，从句中不带宾语。
例如：
1)He studies in such a good school that all other students in his village admire him.
他在那样好的一所学校学习，以至于村子里其他的学生都很羡慕他。
解析：that后是状语从句，状语从句中有宾语him。
2)He studies in such a good school as all other students in his village admire.
他在那样好的一所学校学习，村里的其它学生都很羡慕那所学校。
解析：as后是定语从句,as代替先行词school,在定语从句中做admire的宾语。
