19.4 目的状语从句

　 表示目的状语的从句可以由that, so that, in order that, lest, for fear that, in case等词引导，例如： 　 You must speak louder so that /in order that you can be heard by all. 　 He wrote the name down for fear that(lest) he should forget it. 　 Better take more clothes in case the weather is cold.

19.3 原因状语从句 比较：because, since, as和for 1)　because语势最强，用来说明人所不知的原因，回答why提出的问题。当原因是显而易见的或已为人们所知，就用as或 since。 　 I didn't go, because I was afraid. 　 Since /As the weather is so bad, we have to delay our journey. 2)　由because引导的从句如果放在句末，且前面有逗 号，则可以用for来代替。但如果不是说明直接原因，而是多种情况加以推断，就只能用for。 　 He is absent today, because / for he is ill. 　 He must be ill, for he is absent today.

19.2 方式状语从句 　方式状语从句通常由as, (just) as…so…, as if, as though引导。 1) as, (just) as…so…引导的方式状语从句通常位于主句后，但在(just) as…so…结构中位于句首，这时as从句带有比喻的含义，意思是"正如…"，"就像"，多用于正式文体，例如： 　Always do to the others as you would be done by. 　你希望人家怎样待你，你就要怎样待人。 　As water is to fish, so air is to man. 　我们离不开空气，犹如鱼儿离不开水。 　Just as we sweep our rooms, so we should sweep backward ideas from our minds. 　正如打扫房屋一样，我们也要扫除我们头脑中落后的东西。 2) as if, as though 　 两者的意义和用法相同，引出的状语从句谓语多用虚拟语气，表示与事实相反，有时也用陈述语气，表示所说情况是事实或实现的可能性较大。汉译常作"仿佛……似的"，"好像……似的"，例如： 　They completely ignore these facts as if (as though) they never existed. 　他们完全忽略了这些事实，就仿佛它不存在似的。(与事实相反，谓语用虚拟语气。) 　He looks as if (as though) he had been hit by lighting. 　他那样子就像被雷击了似的。(与事实相反，谓语用虚拟语气。) 　It looks as if the weather may pick up very soon. 看来天气很快就会好起来。(实现的可能性较大，谓语用陈述语气。) 　说明：as if / as though也可以引导一个分词短语、不定式短语或无动词短语，例如： 　He stared at me as if seeing me for first time. 他目不转睛地看着我，就像第一次看见我似的。 　He cleared his throat as if to say something. 他清了清嗓子，像要说什么似的。 　The waves dashed on the rocks as if in anger. 波涛冲击着岩石，好像很愤怒。

19.1 地点状语从句 　地点状语从句通常由where, wherever 引导。 　Where I live there are plenty of trees. 　我住的地方树很多。 　Wherever I am I will be thinking of you. 　 不管我在哪里我都会想到你。

18.9 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。 　　 (错)　The tree, that is four hundred years old, is very famous here. 　b) 介词后不能用。 　　 We depend on the land from which we get our food. 　　 We depend on the land that/which we get our food from. 2) 只能用that作为定语从句的关系代词的情况 　a)　在there be 句型中，只用that，不用which。 　b)　在不定代词，如：anything, nothing, the one, all, much, few, any, little等作先行词时，只用that，不用which。 　c)　先行词有the only, the very修饰时，只用that。　 　d)　先行词为序数词、数词、形容词最高级时，只用that。. 　e)　先行词既有人，又有物时。 举例： 　 All that is needed is a supply of oil. 　 所需的只是供油问题。 　 Finally, the thief handed everything that he had stolen to the police.　 　 那贼最终把偷的全部东西交给了警察。

状语从句

18.7 先行词和关系词二合一 　1)Whoever spits in public will be punished here. 　 (Whoever 可以用 anyone who 代替) 　2)The parents will use what they have to send their son to technical school. 　(what 可以用all that代替) 18.8 what/whatever;that/what; who/whoever 1)what = the thing which；whatever = anything 　　What you want has been sent here. 　　Whatever you want makes no difference to me. 2) who= the person that　 whoever= anyone who 　 (错)Who breaks the law will be punished. 　 (错)Whoever robbed the bank is not clear. 　 (对)Whoever breaks the law will be punished. 　 (对)Who robbed the bank is not clear. 3) that 和 what　 　当that引导定语从句时 ，通常用作关系代词，而引导名词性从句时，是个不充当任何成分的连接词。宾语从句和表语从句中的that常可省略。What只能引导名词性从　句， 用作连接代词，作从句的具体成分，且不能省略。 　I think (that) you will like the stamps. 　What we need is more practice.

18.6 as, which 非限定性定语从句 　由as, which 引导的非限定性定语从句，as和which可代整个主句，相当于and this或and that。As一般放在句首，which在句中。 　As we know, smoking is harmful to one's health. 　The sun heats the earth, which is very important to us.　 典型例题　 1)Alice received an invitation from her boss, ___came as a surprise. A. it　 B. that　 C. which　D. he 　 答案C. 此为非限定性从句，不能用 that修饰，而用which.，it 和he 都使后句成为句子，两个独立的句子不能单以逗号连接。况且选he句意不通。 2)The weather turned out to be very good, ___ was more than we could expect. A. what　B. which　C. that　D. it 　 答案B。which可代替句子，用于非限定性定语从句，而what不可。That 不能用于非限定性定语从句，it不为连词，使由逗号连接的两个句子并在一起在英语语法上行不通。 3)It rained hard yesterday, ____ prevented me from going to the park.. A. that　B. which　C. as　 D. it 　答案B. 　as 和which在引导非限制性定语从句时，这两个关系代词都指主句所表达的整个意思，且在定语从句中都可以作主语和宾语。但不同之处主要有两点： 　(1) as 引导的定语从句可置于句首，而which不可。 　(2) as 代表前面的整个主句并在从句中作主语时，从句中的谓语必须是系动词；若为行为动词，则从句中的关系代词只能用which.。 　 在本题中，prevent由于是行为动词，所以正确选项应为B。 As 的用法 例1. the same… as；such…as 中的as 是一种固定结构, 和……一样……。 　 I have got into the same trouble as he (has). 例2. as可引导非限制性从句，常带有'正如'。 　As we know, smoking is harmful to one's health. 　As is know, smoking is harmful to one's health. 　As是关系代词。例1中的as作know的宾语；例2中，它充当从句的主语，谓语动词know要用被动式。

18.5 介词+关系词 1)介词后面的关系词不能省略。 2)that前不能有介词。 3) 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 和where 互换。 　 This is the house in which I lived two years ago. 　 This is the house where I lived two years ago. 　 Do you remember the day on which you joined our club? 　 Do you remember the day when you joined our club?

18.4 限制性和非限制性定语从句 1) 定语从句有限制性和非限制性两种。限制性定语从句是先行词不可缺少的部分，去掉它主句意思往往不明确；非限制性定语从句是先行词的附加说明，去掉了也不会影响主句的意思，它与主句之间通常用逗号分开，例如： 　　This is the house which we bought last month.　　这是我们上个月买的那幢房子。(限制性) 　　The house, which we bought last month, is very nice.这幢房子很漂亮，是我们上个月买的。(非限制性) 2) 当先行词是专有名词或物主代词和指示代词所修饰时，其后的定语从句通常是非限制性的，例如： 　　Charles Smith, who was my former teacher, retired last year. 查理·史密斯去年退休了，他曾经是我的老师。 　　My house, which I bought last year, has got a lovely garden.　我去年买的的那幢房子带着个漂亮的花园。 　　This novel, which I have read three times, is very touching. 这本小说很动人，我已经读了三遍。 3) 非限制性定语从句还能将整个主句作为先行词, 对其进行修饰, 这时从句谓语动词要用第三人称单数，例如： 　　He seems not to have grasped what I meant, which greatly upsets me. 他似乎没抓住我的意思，这使我心烦。 　　Liquid water changes to vapor, which is called evaporation. 液态水变为蒸汽，这就叫做蒸发。 说明：关系代词that和关系副词why不能引导非限制性定语从句。

18.3 判断关系代词与关系副词 　 方法一： 用关系代词，还是关系副词完全取决于从句中的谓语动词。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： 　 This is the mountain village where I stayed last year. 　 I'll never forget the days when I worked together with you. 　 判断改错(注：先显示题，再显示答案，横线；用不同的颜色表示出。) 　 (错) This is the mountain village where I visited last year. 　 (错) I will never forget the days when I spent in the countryside. 　 (对) This is the mountain village (which) I visited last year. 　 (对) I'll never forget the days (which) I spent in the countryside. 　习惯上总把表地点或时间的名词与关系副词 where, when联系在一起。此两题错在关系词的误用上。 　 方法二： 准确判断先行词在定语从句中的成分(主、谓、宾、定、状)，也能正确选择出关系代词/关系副词。 例1. Is this museum ___ you visited a few days age? 　 A. where　B. that　 C. on which　 D. the one 例2. Is this the museum ____ the exhibition was held. 　 A. where　B. that　 C. on which　D. the one 答案：例1 D，例2 A 例1变为肯定句： This museum is ___ you visited a few days ago. 例2变为肯定句： This is the museum ___ the exhibition was held. 　在句1中，所缺部分为宾语，而where, that, on which都不能起到宾语的作用，只有the one既做了主句的表语，又可做从句的宾语，可以省略关系代词，所以应选D。 　而句2中, 主、谓、宾俱全，从句部分为句子的状语表地点，既可用副词where，又因 in the museum词组，可用介词in + which 引导地点状语。而此题中，介词on 用的不对，所以选A。 　关系词的选择依据在从句中所做的成分，先行词在从句中做主、定、宾语时，选择关系代词 (who, whom, that, which, whose)； 先行词在从句中做状语时，应选择关系副词 ( where 地点状语，when 时间状语，why 原因状语) 。