最新if和unless区别和练习资料

1、 精品文档chapter 1 语法if 和 unless 引导的条件状语从句我们用 if 引导的条件状语从句来讨论可能的条件以及该条件成立时可能的结果。一. 学习 if 引导的条件状语从句的用法，我们可先从如下的口诀入手：if 条件句不一般，几个要点记心间；条件句，放在前，逗号要句中间条件句表可能，主句多用将来时；条件句表事实，主句常用现在时。we can walk there if we cant find a bus. 如果我们找不到公车，也能走路去那里主句if it rains tomorrow, we will not go to the zoo. 如果明天下雨，我们就不去动物园条件状

2、语从句 主句what will you go if you find someone in danger?主句 条件状语从句条件状语从句如果你发现某人有危险，你会怎么做？if 条件句有不同的类型，简述如下：1. 用 if 条件句表达客观真理或普通现象if 条件句用于表达客观真理或普通现象时，主，从句时态均用一般现在时，如：eg. if you freeze water, it turns into ice.a fish dies if you take it out of water.2. 用 if 条件句表示将来可能发生的事情在表示将来可能发生的事情的 if 条件句中，主句用一般将来时，而

3、if 从句用一般现在时表示将来的时间，即主将从现eg. if i like the house, i will buy it. 如果我喜欢这房子，我就会把它买下i will tell her if i see her. 如果我见到她，我就会告诉她。主句中的 will 也可以用情态动词 can, may 或 might 等代替。如：eg. if they are friendly，i might invite them to the party. 如果他们很友善，我可能会请他们去参加聚会if we hurry now, we can stop for coffee later. 如果我们现在抓紧

4、时间，就可以稍后去喝咖啡精品文档 精品文档注意：在条件句中，主句部分只能使用动词 will 的一般将来时，不能使用 be going to 的结构二. unless 的条件句表示在特定条件下，才决定做或不做一件事，中文用的连接词一般是“除非”和“否则”。如：除非刮台风，否则演唱会将如期进行。在英语中，我们可以用unless 表达这个意思，相当于 if not。以这个句子为例：the concert will be held as schedule unless there is a typhoon.= the concert will be held as schedule if there

5、is not a typhoonshe will keep on singing unless she is told to stop. 她会一直唱下去，除非有人叫她停止= she will keep on singing if she is not told to stop也可以用 or(否则) 来做同义句转换unless you listen carefully, you wont know the answer.= if you dont listen carefully, you wont know the answer.= you should listen carefully, o

6、r you wont know the answer.深圳中考题：1. if i _ his phone number, i will tell you.a. find2. we will go camping if it _ tomorrow.a. wont rain b. didnt rain c. doesnt rain3. im waiting for my friend. if he _, i _ swimming alone.b. foundc. will findd. have foundd. isnt raininga. doesnt come; will gob. wont

7、come; will god. dont come; will goc.will come; wont go4. _ you go to the supermarket at 7 p.m, you can buy a lot of cheap food.a. if b. unless c. whether d. when5. i wont get to the party on time _ i catch the first train tomorrow morning.a. ifb. unlessc. whetherd. when6. -shall we go on a picnic th

8、is weekend?-good idea! unless it _.a. rainsb. doesnt rainc. raind. wont rain精品文档 精品文档7. -can i change the jacket for another one _ it doesnt fit me well?- of course.a. unlessb. ifc. thathe works hard on it.d howeverd. though8. nobody can learn maths wella if b unless c thought9. if fisha are taking,

9、 wontc are being taken, willaway from water, theydie.b are taken, willd take, wont10. each student can ask teachers for help if hehow to work out the problem.d doesnt knowa will knowb wont knowc dont know练习:a woman should never be seen eating or drinking, unless it be lobster salad andchampagne, the

10、 only true feminine and becoming viands.lord byroni dont feel right unless i have a sport to play or at least a way to work up a sweat.hank aaronno great poetry, of whatever kind, is conceivable unless the subject has becomeintegrated with the poets mind and mood.lascelles abercrombieim not going to

11、 just say nice things about everybody unless i mean it.abrahamf. murrayunless youre willing to have a go, fail miserably, and have another go, success wonthappen. phillip adams1. if i _ you, i _ very happy.a. were, would bec. were, shall beb. am, shall bed. am, would be2. if he had not lost his mone

12、y, he _ the piano last week.a. would buyb. had boughtd. boughtc. could have bought3. _i known it, i should have told him.精品文档 精品文档a. haveb. had c. having d. if4. _ the clouds, you would find the airplane in the sky easily.a. were it not forc. if it were notb. if it had not been ford. had it not been

13、 for5. if i had known that, i _ so.a. wouldnt doc. didnt dob. wont dod. wouldnt have done6. if it _ so hard, wed go to town.a. isnt raining b. werent rainingc. doesnt raind. isnt going to rain1.答案 a 2 答案 c 3.答案 b 4.答案 a 5.答案 d 6.答案 b7. he _ you if you _ to see him that afternoon.a. might tell, were

14、goingb. told, were goingc. might have told, had goned. should tell, went8. if you had started sooner, you _ there.a. may have gotc. shall have gotb. might have gotd. must have got9. if we were to be 2oo years old, we _ everything.a. will changeb. can changed. shall changec. could change10. i dont th

15、ink that i shall fail, but if i _ i would try again.a. failb. would faild. had failedc. should fail11. if you _ to see mary, what would you tell her?a. areb. will be going精品文档 精品文档c. mustd. were12. if the train leaves at half past ten, there _ no time to lose.a. would b. is c. will d. has7.答案 c 8.答案

16、 b 9.答案 c 10.答案 c 11.答案 d 12.答案 bunless“除非，如果不”(=ifnot)例句 wi shall go tomorrow unless it rains. 如果不下雨，我明天去。shall tom go and play football?not unless he has finished his homework. 除非他完成作业，否则不能出去。i wont go unless he comes to invite me himself.w 除非他本人来邀请我，不然我是不会去的。i wont attend his birthday party unless invited (=unless i am invited). 除非被邀请，否则我不去参加的生日晚会。1. the men will have to wait all day _ the doctor works faster.（2001 北京春季）a. i