定语从句定义:定语从句(Attributive Clauses )在句中做定语，修饰一个名词或代词。
被修饰的名词，词组或代词即先行词。
关系代词有：who, whom, whose, that, which关系畐U词有：whe n, where, whyThe man who/ that came first is Joh n.1.关系代词引导的定语从句关系代词所代替的先行词是人或物的名词或代词，并在句中充当主语、宾语、定语等成分。
关系代词在定语从句中作主Example: A prosperity which / that has n ever bee n see n before appears in the coun tryside.The package (which / that) you are carry ing is about to come un wrapped.Is he the man who/that wants to see you?He is the man whom/ that I saw yesterday.They rushed over to help the man whose car had broke n dow n. Please pass me the book whose (of which) cover is gree n.2. 关系副词引导的定语从句关系副词可代替的先行词是时间、地点或理由的名词，在从句中作状语。
1) when, where, why关系副词when, where, why的含义相当于"介词+ which"结构，因此常常和"介词+ which"结构交替使用，例如：Beiji ng is the place where (in which) I was born.Is this the reas on why (for which) he refused our offer?2) 抽象地点地、境况、情况、情形、地步为先行词的时候，用where引导的定语从句。
例题：1. We ' re just trying to reach a point ___ b oth sides will sitdown together and talk.A . whereB . that C. when D . which2. Today, we ' ll discuss a number of cases __ beginners of English fail to use the Ianguage properly.A. whichB. asC. whyD. where3. Many people who had see n the film were afraid to go to the forest whe n they remembered the scenes ___ people were eaten by the tiger.A . in whichB . by which C. which D . that4.1 have reached a point in my life ____ I am supposed to make decisi ons of my own.A. whichB. whereC. whe nD. why3) 某些在从句中充当时间，地点或原因状语的”介词+关系词”结构可以同关系副词when, where, why互换。
This is the house where (in which) I lived two years ago.Do you remember the day whe n (on which) you joined our club?4) 介词/复合介词+关系代词1. Learning strategies, to which (the) teachers attach/ have attached (老师们认为)importanee, have not yet drawn eno ugh atte nti on of stude nts. (attach)2 . My house is in the suburb, in front of which there is a lake (前面有个湖).(front)5) 不定代词some, any, none, both, all, neither, most, each, few + of + 关系代词(1) He loved his pare nts deeply, both of whom are very ki nd to him.(2) In the basket there are quite many apples, some of which have gone bad.(3) There are forty stude nts in our class in all, most of whom are from big cities.6) 形容词的比较级/最高级+ of +关系代词She has three sons,the oldest of whom is a PLA man.(其中最大的一个)(old)7) 名词/数词+ of +关系代词1 . Fin ally came to an old castle, the gate of which was wide ope n.(它的大门)(gate)2. There are sixty students in our class, twenty of whom are girls.(其中二十名)(twenty)［练一练］1. Do you like the book ____________ she spe nt $10?2. Do you like the book ____________ she paid $10?3. Do you like the book ______________ she lear ned a lot?4. Do you like the book ______________ she ofte n talks?5. He built a telescope ________________ h e could study the skies.3判断关系代词与关系副词1 )方法一：判断从句中的谓语动词，及物动词后面无宾语，就必须要求用关系代词；而不及物动词则要求用关系副词。
例如：1. (对) This is the mountain village where I stayed last year.2. (错) This is the mountain village where I visited last year.3. (对) This is the mountain village (which) I visited last year.4. （对）I'll never forget the days when I worked together with you.5. （错）I ' II never forget the day when I spent in the countryside.6. （对）ni never forget the days （which）I spent in the countryside.2）方法二：判断先行词在定语从句中的成分（主、定、宾、状），也能正确选择出关系代词/关系副词。
先行词在从句中做主、定、宾语时，选择关系代词；先行词在从句中做状语时，应选择关系副词。
1. Is this museum __you visited a few days ago?A. whereB. thatC. on whichD. the one2. Is this the museum ___ the exhibiti on was held.A. whereB. thatC. on whichD. the one［练一练］1. This is the library __________ has over 5000 books.2. This is the library ____________ my gran dfather built in 2008.3. This is the library __________ I worked last year.4. This is the reason _________ he was late for school.5. This is the reason _________ he gives me.6. I don ' t like Wae< _________________ y ou speak to your parents.7. The way ______________ he expla ined to us was quite simple.8. It is the third time _________ I have come to China.9. There was a time in history _______________ w ome n had no right to vote.4. 关系代词that的用法1）不用that的情况a）在引导非限定性定语从句时。
（F） The tree, that is four hun dred years old, is very famous here.b）介词后不能用。
（指物用which,指人用whom）We depe nd on the land from which we get our food.We depe nd on the land that/which we get our food from.2）只能用that不用which作为定语从句的关系代词的情况a）在不定代词anything, nothing, the one, all, much, few, any, little 等作先行词时，只用that，不用which。
There seems to be nothing that seems impossible for him in the world.b）先行词有the only, the very修饰时，只用that。