语法专题一：定语从句1. 定语从句的几个基本概念：1) 先行词：即被定语从句修饰的名次或代词，通常位于定从的前面。
2) 先行词在从句中担当成份：根据不同成份，用相应的关系代词或关系副词。
3) 关系代词：即先行词在定从中作主、宾、表、定。
作主语：指物，则用that, which引导，且不能省略；指人，用that, who引导，不省略。
作宾语：即及物动词宾语和介词宾语：指物，用that, which引导，可省略；指人，用that, who, whom引导，可省略。
注意：如将介词提到了定从之首，先行词指人，只能用whom; 指物只能用which。
作表语：一般指人、指物皆用that, 可省略。
作定语：指人、指物皆用whose,不省略。
4) 关系副词：即先行词在定从中作状语，指时间用when, 地点用where, 原因用why，亦可用介词+which替代。
所谓作状语：即先行词不能直接放入从句中，需要有一个介词连接，而从句中却没有这个介词。
5) 非限制性定语从句：即用逗号与主句或先行词分开，用于补充说明。
(1) which: 用于指代先行词（物），或整个主句，不能省略。
(2) who / whom: 用于指代先行词（人），不能省略。
(3) all / some of + which / whom: 用于指代先行词的部分。
(4) as为关系代词，“正如、就像”的意思, 引导定从时可置于句首、句中或句末。
注意：在非限制性定从中，不能用that。
2. 一些特殊用法：1) 一般只用that引导从句的情况：(1) 限制性定语从句中，当先行词被强调，如被any, every, each, few, little, no, some, theonly, the very等修饰时；(2) 先行词是不定代词all, few, little, much, something, nothing, anything等时；(3) 先行词被序数词或形容词的最高级所修饰时；(4) 先行词既有人又有物时；(5) 当句中已有who时，为避免重复。
2) 一般只用which引导从句的情况：(1) 引导非限制性定语从句，指前面的某名词或它前面的整个主句时；(2) 引导介词、介词短语提前的定语从句时；(3）当先行词为集体名词时，着眼于整体，用which；着眼于各个成员，用who；(4) 替代某些固定短语中的指示代词，如this, that等, 引导定从。
3) 由as引导的定语从句的几种常见情况：(1) as引导非限制性定语从句，说明整个主句的内容，和which引导定语从句代替整个句子的区别是：which不能放在句首，而as则可以；在句中，as有“正如”、“就象”之意，而which则没有此意；(2）当先行词前有the same，such修饰时，或在“so / as…as”结构中，表示“那样……以致”，后用关系代词as引导限制性定语从句；(3) 在such…as结构中，as为关系代词，替代先行词，引导的是定语从句；在such…that结构中，that为连词，引导的是一个完整的结果状语从句。
4) 当way作先行词时，可用that, in which或省略引导定从5) 当先行词为situation, case, point, job, condition等时，常用where引导定从。
6) 当先行词为one of the +复数名词时，定从的谓动用复数动词；当先行词为the (only)one of the +复数名词时，定从的谓动用单数动词；巩固练习：1. Last month, part of Southeast Asia was struck by floods, from ______ effects the people are stillsuffering.A. thatB. whoseC. thoseD. what2. Mark was a student at this universit y from 1999 to 2003, ______ he studied very hard and wasmade Chairman of the Students’ Union.A. during which timeB. for which timeC. during whose timeD. by that time3. I work in a business ______ almost everyone is waiting for a great chance.A. howB. whichC. whereD. that4. The English play ______ my students acted at the New Year’s party was a great success.A. for whichB. at whichC. in whichD. on which5. New York, ______ I visited last year, is a nice old city.A. thatB. whichC. whenD. in which6. I can think of many cases ______ students obviously knew a lot of English words andexpressions but couldn't write a good essay.A. whyB. whichC. asD. where7. George Orwell, ______ was Eric Arthur, wrote many political novels and essays.A. the real nameB. what his real nameC. his real nameD. whose real name8. ______ is reported in the newspaper, talks between the two countries are makingA. ItB. AsC. ThatD. What9. American women usually identify their best friend as someone ______ they can talk frequently.A who B. as C. about which D. with whom10. Anyway, that evening, ______ I'll tell you more about later, I ended up staying at Rachel'splace.A. whenB. whereC. whatD. which11. The factory ______ the students visited last week is the one ______ I have worked for theeyears.A. that; whichB. when; in whichC. /; whereD. which; that12. The most important thing _____ we should pay attention to is the first thing ____ I have said.A. which; thatB. that; whichC. which; whichD. that; that13. The school ______ my father teaches is a world-famous one, ______was set up 100 years ago.A. where; whichB. which; whichC. /; whereD. where; that14. This is Mr. Smith, ______ I think has something interesting to tell you.A. whoB. whomC. thatD. /15. ______ is known to everybody, the moon travels round the earth once every month.A. ItB. AsC. Th atD. What16. ---When was the house built?---It was built in 1949 ______ the PRC was founded.A. whichB. thatC. whatD. when17. He never reads anything ______ is not worth reading.A. asB. whichC. whoD. that18. He has three brothers, ______ is a doctor.A. all of themB. all of whomC. none of whomD. both of them19. The young mother saw her baby fall to the ground, ______ brought her heart to her mouth.A. itB. and thatC. and whichD. that20. Is this the reason ______ he explained at the meeting for his carelessness in his work?A. thatB. whatC. howD. why21. The place ______ interested me most was the Gnat Wall.A. in whichB. whichC. whereD. what22. The Oscar is one of the film prizes ______offered to any Chinese actor or actress so far.A. which are notB. that have not beenC. that has notD. that has not been23. I'd like a car ______ front lights are big and tuned.A. whichB. thatC. whoseD. of which24. You were very impolite to him, for ______ you should make an apology to him, I think,A. thisB. whichC. whatD. that25. The artist ______ the judge gave a prize is the teacher ______ I have been taught painting fortwo years.A. from whom; by whomB. to whom; whoC. from whom; whoD. to whom; by whom26. For weeks the street hasn't been cleaned by the cleaners, ______ makes it very dirty.A. whoB. whichC. thatD. this27. Now teenagers like t o go to the fast food restaurants, ______ eating doesn’t take much time.A. whichB. whoC. whatD. where28. In my old school album there are some pictures of some teachers ______ can’t be f ound inyours.A. whichB. whoC. thoseD. they29. Henry set up a club for football fans, ______ he invited all his friends.A. for whomB. to whomC. to whichD. from which30. His parents wouldn't let him marry anyone ______ family was poor.A. of whomB. whomC. of whoseD. whose31. The weather turned out to be very good, ______ was more than we could expect.A. whenB. whichC. thatD. when32. After living in Paris for fifty years he returned to the small town ______ he grew up as a child.A. whichB. whereC. thatD. when33. Carol said the work would be done by October, ______ personally I doubt very much.A. itB. thatC. whenD. which34. Dorothy was always speaking highly of her role in the play, ______, of course, made theothe rs unhappy.A. whoB. whichC. thisD. what35. I bought an ancient Chinese vase, ______ was very reasonable.A. which priceB. the price of whichC. its priceD. the price of whose36. ______ has already been pointed out, grammar is not a set of dead rules.A. AsB. ItC. ThatD. Which37. He lived in London for 3 months, during ______ time he learned some English.A. thisB. whichC. thatD. same38. On the wall hung a picture,______ colour is blue.A. whoseB. of whichC. whichD. its39. Whenever I met him, ______ wa s fairly often, I like his sweet and hopeful smile.A. whatB. thatC. whichD. when40. He bought a book that could give him much knowledge and ______ could help him to kill thetime.A. thatB. whereC. whichD. there41. The boss ______ department Ms. King worked ten years ago looked down upon women.A. in whichB. in thatC. in whoseD. whose42. Luckily, we'd brought a mad map without ______ we would have lost our wa y.A. itB. thatC. thisD. which43. He made another wonderful discovery, ______ of great importance to science.A. which I think isB. which I think it isC. which I think itD. I think which is44. This is the very bag ______ my mother bought yesterday.A. thatB. whoC. whomD. which45. I think you have got to the point ______ change is needed, or you would failA. whenB. thatC. whereD. which46. October 1, 1949 was the day ______ the People’s R epublic of China was founded.A. whichB. whenC. whereD. in which47. Is this the shop ______ sells children’s clothing?A. whichB. whereC. in whichD. what48. Is this museum ______ they visited last month?A. thatB. whichC. whereD. the one49. I still remember the sitting-room ______ my mother and I used to sit in the evening.A. whatB. whichC. thatD. where50. She was not the woman ______ she was before.A. whatB. whoC. thatD. where定语从句：BACCBDDBDDCDAABBDCBABBCBDBDACDBBDBBABACCCDAACBADDC。