掌握从句要点，选择合适的连接词。 定语从句中的关系词要作成分，关系代词that,
which，as通常作主语或宾语；whose作定语；关系副词where，when，why通常作状语。that在其引导的名词性从句中只起引导作用，不作成分；而连接词what在从句中起双重作用，既作成分又能引导句子。做题时，首先要分析从句成分，选择合适的连接词。例如： As a mother，I seldom give my children so difficult a job________they can't do actively. A．thatB．as C．whichD．if
[解析]在so...that结构中that引导的是状语从句，状语从句的结构完整，that在句子中不作成分。so...as结构中，as引导定语从句，as在定语从句中作主语或宾语。如果选that的话，do后面缺少宾语，句子结构就不完整了。分析job后面的句子可知，动词do缺少宾语，故空格处要填一个关系代词来引导一个定语从句修饰job；考虑到前面的so，这里应填as与之搭配。不要把这个句子看成是so...that结构。 [答案] B
语法精要十 定语从句
1.关系代词引导的定语从句 引导定语从句的关系代词有who，that，whom，which，whose，as。如： The book that(which) he is reading was written by LuXun. 他正在读的那本书是鲁迅写的。 She is a student(whom/that)we should learn from 她是个我们该向她学习的学生。 Is there anyone in your class whose mother is a doctor? 你们班是否有母亲是医生的同学？ He usually has a short sleep after lunch，as is his habit. 正如他的习惯，他总是在午饭后小睡一会儿。 Such a person as you described doesn't exist. 像你描述的这样一个人不存在。
2．由关系副词引导的定语从句
引导定语从句的关系副词有when，where，why。如： He will always remember the day when his father returned from America. 他将永远记得他父亲从美国回来的那一天。 The factory where his father works is the largest one in this city. 他父亲工作的这个工厂是这个城市最大的工厂。
I don't know the reason why he was absent today. 我不知道他今天没来的原因。 3．非限制性定语从句
根据定语从句与先行词之间的关系，定语从句分为限制性定语从句和非限制性定语从句。限制性定语从句与先行词关系密切，起限制作用，不可去掉，中间无逗号隔开。非限制性定语从句只对主句起补充说明的作用，如去掉从句，主句也能独立存在，意思仍然完整，从句与主句间往往有逗号分开。引导非限制性定语从句的引导词有which，who，whom，whose，as，where，when(that不可引导非限制性定语从句)。如： The new house，which is situated at the foot of the mountain，has no electricity. 坐落于山脚下的这座新房子没有电。 He has gone to America，where he will stay for two years. 他已经去美国了，他将在那里待两年。 As we know，Canada is the second largest country in the world. 正如我们所知，加拿大是世界上第二大国。
4．关系代词that与which的区别 (1)只用that引导的定语从句 that在定语从句中可以指人也可以指物，在定语从句中作主语或宾语，可以代替who，whom，which等。下列情况下只用that(作宾语时可以省略)而不用which引导定语从句。 ①先行词被序数词修饰时。 The first English novel(that)I read was A Tale of Two Cities.
我读的第一本英文小说是《双城记》。 ②先行词被形容词的最高级修饰时。 It is the best film(that)I have ever seen. 它是我看过的最好的电影。
③先行词是all，everything，something，anything，nothing，none等不定代词时。 Is this all that is left？这就是全部剩下的吗？ I'll do everything(that)I can to help you. 我将尽我所能帮助你。
④先行词被the only，the very修饰时。 The only thing that matters is to find our way home. 唯一要紧的事是找到我们回家的路。 This is the very book(that) I've been looking for. 这就是我们正在找的书。 ⑤当特殊疑问句由who或which引导时，为避免重复，常用that代替who或which引导定语从句。 Who is the man that is standing by the door? 站在门边的那个人是谁？ Which is the dictionary(that)you bought yesterday? 哪一本是你昨天买的字典？
⑥先行词既指人也指物。 Look at the man and his donkey that are walking up the street. 看那个在街上走着的人和他的驴。 (2)用which而不能用that引导的定语从句 ①which可引导非限制性定语从句，that则不能。 He had failed in the maths exam，which made his father very angry. 他没通过数学考试，这令他父亲很生气。 ②在介词提前的定语从句中，只用which，而不用that引导。 This is the house in which Lu Xun used to live. 这是鲁迅曾住过的房子。 5．as与which在引导定语从句时的区别 as与which都可以代指主句中的一部分或整个句子的内容，有时可以互换。 He married her，as(which) was natural. 很自然地，他和她结婚了。 但在下列情况下一般只能用as。 (1)as引导的定语从句可以放在句首，而which则不能。如： As we know，more than seventy percent of the earth is covered with water. 正如我们所知，地球表面的70%以上由水覆盖。 (2)as表示“正如，正像”，而which无此意。 此时，as从句中常有know，expect，happen，point out，plan，suggest等单词或短语。如： He came back home late，as we expected. 正如我们所料，他回家晚了。 As is pointed out，this is a grammar problem. 正如所指出的，这是个语法问题。
People generally agree that American English differs from British English a bit，as is said above. 正如上面所说，大部分人都同意美式英语与英式英语有点不同。 (3)当先行词被the same，such修饰时，定语从句需用as引导。如： I bought the same book as you have. 我买了一本跟你一样的书。 I'll give you such things as you may need. 我将给你你需要的东西。 He'll marry as pretty a girl as he can find. 他将与他能发现的最漂亮的女孩结婚。 但是当先行词被the same修饰时，that也可引导定语从句，但意义有所不同。如： the same…as(指同样或同类的)，the same…that(指同一个) This is the same watch as I lost. 这块表与我丢的那块一样。 This is the same watch that I lost. 这就是我丢的那块表。 6．whose和of whom，of which引导的定语从句 whose是一个表示所属关系的词，在定语从句中作定语，相当于my，his，her，its，their等修饰人或物。of which可以代替whose指物，词序一般是名词＋of which或of which＋名词。of whom可以代替whose指人，词序是名词＋of whom。如：
This is the scientist whose name is known all over the country. ＝This is the scientist the name of whom is known all over the country. 这就是那位全国知名的科学家。 Nobody wants the house whose roof has fallen in. ＝Nobody wants the house the roof of which(或of which the roof)has fallen in. 没有人想要那座屋顶掉落的房子。
7．“介词＋which/whom”中介词的确定 (1)与定语从句中的动词构成搭配。如： The man(who/whom/that)I talked about at the meeting is from Beijing University. ＝The man about whom I talked at the meeting is from Beijing University. 在会议中我与他谈话的那个人是从北京大学来的。 但是在下面一句中for不可以提前，因为look for是动词词组。 This is the person(who/whom/that)you are looking for. 这就是你找的那个人。
(2)与定语从句所修饰的先行词构成搭配。如： He built a telescope，through which he could study the skies. 他架起一架望远镜，通过它他可以研究天空。 He came to a farm，on which he finally settled. 他来到一个农场，最终在那里定居下来了。 8．几种较为复杂的定语从句 (1)way后面的定语从句。 如果先行词way后面的定语从句中缺少宾语或主语，则用that或which。如果定语从句中不缺少主语或宾语，则用in which，that或省略引导词。如： I think the way(that/which)he told me is best. 我认为他告诉我的方法是最好的。
Please tell me the way that you did the job. ＝Please tell me the way you did the job. ＝Please tell me the way in which you did the job. 请告诉我你做工作的方式。 (2)as所引导的某些特殊定语从句。 She will marry as healthy a man as she can find. 她将嫁给她能找到的任何一个健康的人。 I'll provide you with such things as you may need. 我将提供给你可能需要的东西。 He doesn't have such a mind as is necessary to a scientist. 他缺乏科学家所应具有的头脑。 注意下面两句话的表达： ①The book is written in such easy English as I can read. 这本书是用我能读的简单英语写成的。 ②The book is written in such easy English that I can read it. 这本书是用如此简单的英语写成，我都能读懂。 (第一句为as引导的定语从句，as作宾语。 第二句为that引导的结果状语从句。) (3)定语从句中加插入语。如： This is the man who I believe is very honest. 这就是那个我认为很诚实的人。 We feed the children who we think are hungry. 我们喂了那些我们认为很饿的孩子。 关系代词与动词之间有时有一个插入语，有时用逗号断开，有时没有逗号断开。常用于插入语的动词有believe，think，suppose，guess，say等。解题时应注意将插入成分取出，从而使难题化解。 9．分隔式定语从句 定语从句有时不直接紧靠着先行词，中间由一个定语、状语或谓语隔开。如： There is an expression in his eyes that I can't understand. 我不能理解他眼中表达的东西。 The days are gone forever when the Chinese people were looked down upon.
中国人民被轻视的日子一去不复返了。