十四节课串讲四六级语法第五讲条件目的状语从句ppt课件

1、十四节课串讲四六级语法十四节课串讲四六级语法第第5讲条件、目的状语从句讲条件、目的状语从句豌豆群：豌豆群：群：群：66437760一、条件状语从句定义：由引导词if或unless引导的状语从句叫做条件状语从句。在英文中，条件是指某一件事情实现之后状语从句中的动作，其它事情主句中的动作才干发生，通常译作“假设。留意：在含有条件状语从句的复合句中，表示未来时态，主句是普通未来时态，从句要用普通如今时,祈使句或情态动词主将从现原那么主将从现，将并非指未来时，还只表示未来含义的，跟着if后的那句话是从句。二、条件状语从句用法语法引导条件状语从句最常用的连词是if,由if引导的条件状语从句表示在某种条件

2、下某事很能够发生。如： 1 If you ask him , he will help you. 2 If you fail in the exam ，you will let him down. 另外，if从句还表示不可实现的条件或根本不能够存在的条件，也就是一种虚拟的条件或假设，从句多用普经过去时或过去完成时。如： If I were you , I would invite him to the party. I would have arrived much earlier if I had not been caught in the traffic.三、引导词引导条件状语从句的连词

3、有：if假设，unless除非；假设不，as long as除非；只需，supposing假设，on condition that条件是，in case假设。这些词由于出现的频率较小，且用法较复杂一些，所以不如if为大家所熟知罢了。下面就这些词的用法以例句的方式进展一下简单总结。 1、unless conj.除非，假设不，除非在的时候 You will fail to arrive there in time unless you start earlier. Unless it rains , the game will be played.2、on condition(that).在条件下

4、，假设 on condition (that).引导的条件从句是主句事件发生的前提条件或独一条件。 I can tell you the truth on condition that you promise to keep a secret. You can go swimming on condition (that) you dont go too far from the river bank.3、supposing conj.假设，假设 supposing引导的条件从句表示一种假设条件。 Supposing it rains, shall we continue the sports

5、 meeting? Supposing anything should go wrong , what would you do then? 4、provided conj.假设，除非，以假设，除非，以为条件为条件 provided (that) +从句表示一种假设条件。从句表示一种假设条件。 He will sign the contract provided we offer more favorable terms.He wont be against us in the meeting provided that we ask for his advice in advance. 从上

6、述例句可以看出从上述例句可以看出if, unless, on condition (that), supposing, provided等词引导的条件状语从句，主从句条件关等词引导的条件状语从句，主从句条件关系清楚，构造明晰。系清楚，构造明晰。 但有些句子，虽没有含条件关系的连词，却也隐含着条件关但有些句子，虽没有含条件关系的连词，却也隐含着条件关系，这些句子常用一些词，如系，这些句子常用一些词，如but for , without等引出一个介词等引出一个介词构造来表示条件，条件经常是虚拟的，或与现实相反的假设。构造来表示条件，条件经常是虚拟的，或与现实相反的假设。 如：but for假设非，

7、要不是 But for the rain, we should have a pleasant journey. But for your help, we should not have finished in time.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.

8、专题二、目的状语从句专题二、目的状语从句一、目的状语从句定义目的状语从句：从句部分是用以补充阐明主句中谓语动词发生的目的的。 引导目的状语从句常用的连词有： that以便，so that以便， in order that为了；以便，Lest免得；唯恐， for fear that生怕；以免。 目的状语从句的谓语常含有may, might, can, could, should, wouldYou must speak louder so that /in order that you can be heard by all. He wrote the name down for fear th

9、at(lest) he should forget it. Better take more clothes in case the weather is cold. 学习目的状语从句应留意以下两点： 1目的状语从句中常含有can , could, may, might, should等情态动词。 I got up early so that I could catch the first bus. 2在口语中so可以引导目的状语从句。 Well sit nearer the front so we can hear better. 【留意】in order that与in order to的

10、区别： in order that+从句 in order to+动词原形 in order to后面加的那个不叫目的状语从句，叫目的状语 练习题练习题1.(07全国26)I wont call you，_ something unexpected happens.A. unless B. whether C. because D. while2.(07湖南33)Most brids find it safe to sleep in the trees，but _ they have eggs or young chicks，they dont use a nest.A. why B. how

11、 C. unless D. where3 My parents live in a small village. They always keep candles in the house _ there is a power out.A .if B. unless C in case D. so that4 In time of serious accidents，_ we know some basic things about first aid，we can save lives.A. whether B. until C. if D. unless5.(05北京33)Id like to arrive 20 minutes early _ I can have time for a cup of tea.A. as soon as B. as a result C. in case D. so that6.(08山东31) Youd be