1、条件状语从句,状语：,状语是句子的重要修饰成分。状语是谓语里的另一个附加成分,它附加在谓语中心语的前面,从情况,时间,处所,方式,条件,对象,肯定,否定,范围和程度等方面对谓语中心进行修饰或限制。用来说明地点、时间、原因、目的、结果、条件、方向、程度、方式和伴随状况等。,条件状语从句,定义 由连接词if或unless引导的状语从句叫做条件状语从句。（注意：在含有条件状语从句的复合句中，如果主句是一般将来时态，从句要用一般现在是主将从先原则)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）才能发生，通常译作“假如，如果，除非”。,He will help you
2、 if you ask him.,条件状语从句的位置 可放在句首或句尾，放在句首时常用逗号与主句隔开。,引导词：,常用引导词：if , unless 特殊引导词: as long as（除非；只要），in case（如果）,If 引导词用法 if 引导的条件句有：真实条件句和虚拟条件句两种: 1.真实条件句：表示在某种条件下某事很可能发生。 如: If you ask him, he will help you. 如果你请他帮忙,他会帮你的。 If you fail in the exam, you will let him down. 如果你考试不及格,你会让他失望的。 If it rain
3、s tomorrow, we wont go on a picnic. 如果明天下雨，我们就不去野餐。 注意：在含有条件状语从句的复合句中，表示将来时态，主句是一般将来时态，从句要用一般现在时主将从现原则，并且，切记紧跟着if的那句话是从句。）,2. 虚拟条件句是虚拟语气的一种，表示与事实相反 ，不可实现的条件或根本不可能存在的条件,也就是一种虚拟的条件或假设,从句多用一般过去时或过去完成时。 如: If I were you, I would invite him to the party. 如果我是你,我会邀请他参加聚会。 I would have arrived much earlier
4、 if I had not been caught in the traffic. 如果没有堵车,我会到的早一点儿。 If I were you, I would go with him. 如果我是你,我会和他一起去的。,unless引导词用法 固定搭配： unless = if.not 除非,若不,除非在的时候 You will fail to arrive there in time unless you start earlier. If you dont start earlier, you will fail to arrive there in time. 如果你不早点动身,你就不
5、能及时赶到那儿。 Unless it rains, the game will be played. If it dosent rain，the game will be played. 除非下雨,比赛将照常进行。 Lets go out for a walk unless you are too tired. If you are not too tired, lets go out for a walk. 经典语句： If it dosent rain tomorrow ,we will go to the zoo. 条件状语从句就是用以表示“在某种条件下,会”,由as (so) long
6、 as, in case引导。E.g. So long as youre happy, it doesnt matter what you do.只要你高兴，你做什么都没有关系。You may borrow my book as long as you keep it clean.只要你保持书的清洁，你就可以把我的书借去。Take your umbrella in case it rains. 带着你的伞吧，以防下雨。,1._you call me to say youre not coming，Ill see you at the theatre.(2004吉林27) A.Though B.
7、Whether C.Until D.Unless2.-What would you do if it _ tomorrow？ -We have to carry it on，since weve got everything ready.(2005全国I9) A.rain B.rains C.will rain D.is raining3.You must keep on working in the evening_you are sure you can finish the task in time.(2005安徽22) A.as B.if C.when D.unless4._youve
8、 tried it，you cant imagine how pleasant it is.(2006北京33) A.Unless B.Because C.Although D.When,D,B,D,A,5.In time of serious accidents，_we know some basic things about first aid，we can save lives.(2006重庆23) A.whether B.until C.if D.unless6.We wont keep winning games_we keep playing well.(2006浙江2) A.be
9、cause B.unless C.when D.while7._environmental damages is done，it takes many years for the ecosystem to recover.(2006江苏31) A.Even if B.If only C.While D.Once8.How can you expect to learn anything_you never listen？(2006山东31) A.in case B.even if C.unless D.when,C,B,D,D,1.The WTO cannot live up to its n
10、ame _ it does not include a country that is home to one fifth of mankind. A. as long as BWhile Cif Deven though 2. It is known to all that _ you exercise regularly, you wont keep good health. (05重庆) A. unless B. whenever C. although D. if 3.(10山东)The school rules state that no child shall be allowed
11、 out of the school during the day, _ accompanied by an adult. A. once B. when C. if D. unless 4.(09陕西)My parents dont mind what job I doI am happy. even though B. as soon as C. as long as D. as though 5._ I can see, there is only one possible way to keep away from the danger. （04北京） A. As long as B. As far as C. Just as D. Even if 6. I always take something to read when I go to the doctors _ I have to wait. （05全国） Ain case Bso that Cin order Das if,C,A,D,C,B,A,条件状语从句,
