请问有谁可以教我[定语从句]啊?

请问有谁可以教我[定语从句]啊?
想请问定语从句到底是怎样的...我好多不理解哦~
有没有人教教我啊~最好从头教到尾..我有好多知识点不懂啊...

定 语 从 句
I. 考点分析
定语从句主要考点是关系代词,尤其是that, as, 介词+which的用法.
II．知识点
定语从句也称形容词性从句,在整个句子中起定语的作用.定语从句通常置于它所修饰的名词和代词之后,这种名词和代词被称为先行词.
引导定语从句的关联词为关系代词和关系副词.其中,关系代词有who, whom, whose, that, which等,在从句中可作主语、宾语,定语等；关系副词有when, where, why等词,在定语从句中只用作状语.其中：
1. who, whom, whose指人,在从句中分别作主语（在非正式英语中也可作宾语,但可省略）、宾语和定语；whose也可指物,作定语；that可指人,也可指物,在从句中可作主语,也可作宾语；which指物,在从句中可作主语,也可作宾语.注意：whom, that, which在从句中作宾语时可以省略.请看例句：
1）The man who was here yesterday is a painter.
2) The man (who) I saw is called Smith.
3) I know the man (whom) you mean.
4) A child whose parents are dead is called an orphan.
5) I'd like a room whose window looks out over the sea.
6) A letter that is written in pencil is hard to read.
7) The letter (that) I received from him yesterday is very important.
8) Is he the man that sells eggs?
9) That is the boy (that) you are looking for.
2. When 指时间,where指地点,why指原因,在从句中都作状语.例如：
1) We will put off the picnic until next week when the weather may be better.
2) He has reached the point where a change is needed.
3) That is no reason why you should leave.
定语从句可分为限定性定语从句和非限定性定语从句两种.限定性定语从句一般紧跟在先行词的后面修饰、限定先行词,它与先行词之间没有逗号,去掉后会影响全句意思的完整性.非限定性定语从句用来解释、说明先行词或主句所指内容,与先行词之间用逗号隔开.
1) I like to chat with John, who is a clever fellow.
2) Water, which is a clear liquid, has many uses.
III．定语从句中的四级考点:
1.在下列情形下只能用that,而不能用which.
1)序数词或最高级形容词修饰先行词时：
a. The first English novel that I read was the Tale of Two Cities by Charles Dickens.
b. Tom is the most diligent students that I have ever known.
2) 先行词是不定代词或被All, everything, nothing, anything, something等不定代词修饰先行词时：
a. Mr. Green had told us something that we should do in the summer vocation.
b. I heard all that she told to her mother.
2. that, which 和as
非限定性定语从句中的先行词在从句中作主语指人、指物或主句所指代的一个意义时,引导词不能用that,而只能用which或 as.而后两者的区别是which引导的非限定性定语从句可放在句中和句末,却不能置于句首,as引导的从句既可放在句中、句末,也可置于句首.
a. He once helped a woman, which(as) was reported in the newspaper.
The dog, which(as) is black, is running toward the strange man.
b. As is known, the director of the company is going to come to our branch to have a inspection of the production here.
3. which和whom在从句中作介词的宾语时,介词一般放在二者之前,也可放在从句原来的位置上,在含有介词的固定词组中介词只能放在原来的位置上,而不能放在二者之前.
a. Please tell me from whom you borrowed the English novel.
Please tell me whom you borrow the English novel from.
b. The house in which he lived before now becomes a restaurant.
The house which he lived in before now becomes a restaurant.
c. This is the magazine (that) you are looking for.
4. 介词＋which的结构可代替定语从句中的引导词when和where.
a. He was born in Germany where(in which) he stayed for 12 years.
b. She arrived at 12 o’clock when(at which) it was raining hard.
5.but, than也可作关系代词.
a. You spent more money than was intended to be spent.
b. There are very few but admire his talents.（很少有人不赞赏他的才干的.but = who don't）
从历年四级词汇语法考点中分析可知,定语从句出现的频率很高,主要集中在以上所讲的定语从句的特殊用法中,因此需重点掌握这些.此外,在做题和复习过程中要活学活用.
IV. 历届四级试题中的定语从句：
1. Helen was much kinder to her youngest child than she was to the others,____, of course, made others jealous. (93/06/59)
A) who B) that C) what D) which
2.____ is known to the world, Mark Twain is a great American writer. (93/06/67)
A)That B) Which C) As D) It
3. The residents, ____ had been damaged by the flood, were given help by the Red Cross. (93/6/68)
A)all their homes B) all whose homes C) all of whose homes D) all of their homes
4. Language is a city, to the building of ____ every human being brought a stone. (94/01/51)
A)which B) that C) it D) this
5. You will want two trees about ten feet apart, from ____ to suspend your tent. (95/06/50)
A)there B) them C) which D) where
6. ____ might be expected, the response to the question was very mixed. (96/6/27)
A)As B) That C) It D) What
7. It is useful to be able to predict the extent ____ which a price change will affect supply and demand. (97/01/29)
A)from B) with C) to D) for
8. Living in the central Australian desert has its problems, ____obtaining water is not the least. (98/01/42)
A)for which B) to which C) of which D) in which
9. The British are not so familiar with different cultures and other ways of doing things, ____ is often the case in other countries. (98/06/58)
A) as B) what C) so D) that
10. We need a chairman ____.（98/06/62）
A) for whom everyone has confidence B) in whom everyone has confidence
C) who everyone has confidence of D) whom everyone has confidence on
11. The course normally attracts 20 students per year, ___ up to half will be from overseas. (98/06/70)
A) in which B) for which C) with which D) of whom
12. A survey was carried out on the death rate of new-born babies in that region, ___ were surprising. (99/01/42)
A) as results B) which results C) the results of it D) the results of which
13. He came back late, ___ which time all the guests have already left. (99/06/41)
A) at B) after C) by D) during
14. I hope all the precautions against air pollution ____ suggested by local government will be seriously considered here. (99/06/53)
A)as B) while C) after D) since
15. I've never been to Beijing, but it is the place ___. (99/06/55)
A)that I want to visit it most B) where I'd like to visit
C) in which I'd like to visit D) I most want to visit
16. Beer is the most popular drinks among drinkers,____ overall consumption is significant.(00/06/32)
A)whose B) which C) that D) what
17. The professor could hardly find sufficient grounds ___ his arguments in favor of the new theory. (00/06/36)
A)to be based on B) to base on C) which to base on D) on which to base
18. Living in the western part of the country has its problem, ___ obtaining fresh water is not the least. (00/06/46)
A)with which B) for which C) of which D) which
19. The hours ____ the children spend in their one-way relationship with television people undoubtedly affect their relationship with real-life people. (01/1/54)
A)when B) on which C) that D) in which
20. Agriculture was a step in human progress ___ which subsequently there was not anything comparable until our own machine age. (01/01/64)
A)to B) in C) for D) from
21. Government reports examination compositions legal documents and most letters are the main situations ___ formal language is used. (01/06/46)
A)in which B) on which C) in that D) at what
22.The residents, ____ had been damaged by the fire, were given help by the Red Cross. (02/6/64)
A) all of their homes B) all their homes C) whose all homes D) all of whose homes
23. These people once had fame and fortune; now ____ is left to them is utter poverty. (02/6/61)
A) all that C) all which B) all what D) that all