专题21 定语从句易错点解题方法定语从句：修饰某一名词或代词的从句叫定语从句。定语从句一般紧跟在它所修饰的先行词之后。被定语从句修饰的词叫先行词。定语从句又分为限制性定语从句和非限制性定语从句两种。定语从句关系词的选择是定语从句的重点和难点。关系词分为关系代词和关系副词，关系词替代先行词在定语从句中作主语、宾语、表语、定语或状语。关系词的选择可从两个方面入手：一是关系词在从句中所作的成分；二是先行词所指。关系词在从句中作主语、宾语、表语或定语时，用关系代词；关系词在从句中作状语时，用关系副词。先行词指人时，关系代词用who, whom, that, whose；先行词指物时，关系代词用which, that, whose。看下面高考真题：1. The factory was built in a secret place, around _ high mountains. A. which wasB. it wasC. which wereD. them were【答案】C.【解析】容易误选A或B，将A、B中的 which 和 it 误认为是其后句子的主语。最佳答案是C，around which were high mountains 是一个由介词+which引出的非限制性定语从句，而在该从句中，主语是 high mountains，around which 是表语，所以句子谓语应用复数were，而不是用单数 was。2. _ is known to everybody, the moon travels round the earth once every month.A. ItB. As C. ThatD. What【答案】B.【解析】容易误选 A，认为此处应填一个形式主语。最佳答案是 B。as 引导的是一个非限制性定语从句。3._ is known to everybody that the moon travels round the earth once every month.A. It B. As C. ThatD. What【答案】A.【解析】 it 为形式主语，真正的主语是后面的 that 从句。最佳答案是 A.4.David is such a good boy _ all the teachers like.A. thatB. who C. asD. whom【答案】C.【解析】此题容易误选A，许多同学一看到题干中的such，再联系到选项中的 that，便认为这是考查such that 句式。况且，这样理解意思也还通顺。最佳答案为C，不是A，因为在such that (如此以至)结构中，that 引导的是结果状语从句，并且 that 在从句中不充当句子成分，若在上句填入 such that ，句末的动词 like 缺宾语。as 用作关系代词，引导定语从句修饰其前的名词 boy，同时 as 在定语从句中用作动词 like 的宾语，句意为所有老师都喜欢的一位好男孩。有的同学还会问，假若选A，能否将其后的 that 视为引导定语从句的关系代词呢？不能，因为当先行词受到 such 的修饰时，其后的定语从句应用关系代词 as 来引导，而不用that。5. The buses, most of _ were already full, were surrounded by an angry crowd.A. thatB. it C. themD. which【答案】D.【解析】容易误选 C，用 them 代指 the buses。最佳答案是D。most of which were already full 为非限制性定语从句，修饰 the buses。6. He had a lot of friends, only a few of _ invited to his wedding.A. whomB. them C. whichD. who【答案】B.【解析】容易误选 A，认为这是非限制性定语从句。最佳答案是B，这不是非限制性定语从句，而是一个独立主格结构，因为空格后的动词 invited 并不是一个完整的谓语，而是一个过去分词。当然，假若在 invited 前加上助动词 were，则是一个非限制性定语从句，答案便应选A。再来改正下列定语从句中的典型错误： 1. Is this the pen your father bought it for you?【答案】去掉it。.【解析】: 解析:定语从句中的关系词在从句中充当一定的成分。 因此从句中不能再出现与关系词作用相同的代词或名词,以避免重复。 误句中省略的关系代词(which/that)作bought的宾语,故it是多余的。2. Have you been to the company where she works there?【答案】去掉 there。.【解析】:关系副词已作了work的地点状语。3. I shall never forget the days when I spent with you.【答案】答案:将when改为which/that。【解析】先行词在定语从句中作spent的宾语,故用which/that,而when在从句中只作时间状语。4. Is this all what you want to say?【答案】将what改为that。.【解析】:先行词为指物的不定代词时,其后的定语从句用that来引导,作宾语时也可省略。而what不能引导定语从句。5. He lived in a house, in front of it he planted some beautiful flowers.【答案】将it改为which。.【解析】这是一个含有非限制性定语从句的复合句, which在从句中作介词宾语。6. Mother came back on December 21 when was my birthday.【答案】将when改为which。【解析】: which指代时间(December 21)作定语从句的主语。7. This is the ring for which she is looking.【答案】将for移到looking之后。【解析】:look for是固定短语动词,不能够拆开使用。8. Is this history museum that some foreign friends visited last week?【答案】在that前加the one。【解析】:犯这类错误的主要原因是错把this history museum看作是定语从句的先行词。根据句子结构,this history museum应是主句的主语。故应添加一个定语从句的先行词the one作主句中的表语。9. This is the monitor her English is the best in our class.【答案】将her改为whose。【解析】:用whose代替her引起定语从句,修饰先行词the monitor。10. As you know it, he has left for Australia.【答案】去掉it。【解析】:关系代词as作know的宾语,再使用it就重复了。11. The meeting was put off, that was exactly what we wanted.【答案】将that改为which。【解析】:that作为关系代词不能用于非限制定语从句中。此处which指代主句(The meeting was put off)。12. I dont like the way which you treat your mother.【答案】1)在which前加in。 2) 将which改为that。 3) 去掉which。【解析】当先行词the way在定语从句中作状语时,其关系代词可用that/in which或不用。13. He told the good news to those who was present at the meeting.【答案】将was改为were。【解析】:定语从句中的谓语动词,在数和人称上必须与主句中的先行词保持一致。该句的先行词是those, 故应用were。14. The expert visited our school is from Shanghai.【答案】在visited前加who。【解析】关系代词在定语从句中作主语时不能省略。15. Whos the old man whom you just shook hands?【答案】在hands后加上with。【解析】定语从句中的关系代词whom作with的宾语,故介词with不能省略。 精编陷阱题训练1. All of the flowers now raised here have developed from those _ in the forest. A. once they grewB. they grew once C. they once grewD. once grew【答案】C.【解析】 选 C。先行词是 those，可视为 those flowers 之省略。they once grew 前省略了关系代词 which。全句意为：这儿所养的花是由他们曾在森林里种植的花培养出来的。2. In the office I never seem to have time until after 5:30 pm, _ many people have gone home.A. thatB. whichC. whose timeD. by which time【答案】D.【解析】 选D。by which time 引出的是一个非限制性定语从句，其中 by which time 相当于 and by that time。3. Is this the reason _ at the meeting for his carelessness in his work? A. he explainedB. what he explained C. how he explainedD. why he explained 【答案】A.【解析】选 A。注意不能选 D，因为动词 explained 缺宾语，这里把that省略了。4. Luckily, wed brought a road map without _ we would have lost our way. A. itB. thatC. thisD. which【答案】D.【解析】 D。which 指 the road map。That不做介词的宾语。5. When he was working there he caught a serious illness from _ efforts he still suffers. A. whichB. that C. whoseD. what【答案】C.【解析】C。from whose efforts he still suffers 为修饰 a serious