Unit6GrammarA.docx

1、9AUnit6GrammarA&B（条件状语从句）英语中按句子的结构可分三种：简单句 (simple sentence)；并列句 (compound sentence)和复合句 (complex sentence)。简单句：只有一个主语（或并列主语）和一个谓语（或并列谓语）。e.g. He often reads English in the morning. Tom and Mike are American boys. She likes drawing and often draws pictures for the wall newspapers.并列句：由并列连词（and, but,

2、 or等）或分号（;）把两个或两个以上的简单句连在一起构成。e.g. You help him and he helps you. The future is bright; the road is tortuous. 前途是光明的，道路是曲折的。复合句：主句+从句（含有一个或一个以上从句）。主句是一个完整的句子(independent sentence),它可以独立存在。从句是一个不完整的句子,它必须和一个主句连用，不能独立存在。复合句包含：名词性从句（主语从句、宾语从句、表语从句和同位语从句）、定语从句和状语从句等。中学生英文写作中经常使用的从句有：宾语从句, 状语从句和定语从句。今天，我

3、们就来看看状语从句(Adverbial Clauses)。状语是句子的重要修饰成分，一般由副词、介词短语、分词和分词短语、不定式或相当于副词的词或短语来担当。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词进行修饰或限制，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，其位置一般放在句末，但也可放在句首或句中。在复合句中作状语的句子叫状语从句(Adverbial Clauses)。状语从句在主从复合句中作状语，修饰主句中的动词、形容词或副词，按意义可分为时间、地点、原因、目的、结果、条件、行为方式、比较、让步等九种状语从句。一般位于句首或

4、者句末，位于句首，用逗号和主句隔开。现在，我们一起来学习条件状语从句。由连接词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）才发生。并且，切记紧跟着if或unless的那句话是从句。） 如：If anyone rings me, please tell them Ill be back in the office at 4 oclock.要是有人给我打电话，请告诉他们我四点回办公室。He cant see clearly unless he wears glasses.他不戴眼镜就看不清楚。一、 Gramma

5、r A-using if.(if引导的条件状语从句)1、if 意为“如果；假如”，表示在某种条件下某事很可能发生。if引导的条件状语从句可以位于主句之前或之后。如果从句在前，从句和主句间要用逗号隔开。If you ask him, he will help you. 如果你请他帮忙，他会帮你的。If it does not rain tomorrow, we will go hiking. 如果明天不下雨，我们就去远足。If hunters catch a giant panda, they will kill it for its fur.= They will kill it for it

6、s fur if hunters catch a giant panda.If people find baby pandas alone, they will take them away.=They will take them away if people find baby pandas alone. 2、If引导的条件状语从句中，主句中的动词常用一般将来时，也可含有情态动词或是祈使句。从句均用一般现在时。主将从现原则Ill pay you double if you get the work finished by Friday.如果你周五前完工，我付你双倍的报酬。Dont miss

7、 the programme if you like music.如果你喜欢音乐，不要错过这个节目。If it is fine tomorrow, we can go and fly the kite.如果明天天气好，我们可以去放风筝。二、 Grammar B-using unless.(unless引导的条件状语从句)1、unless 意为“除非，如果不，若不，除非在的时候”，相当于if not（Unless=If not）。在unless引导的条件状语从句中,主句中的动词常用一般将来时，也可含有情态动词或是祈使句。从句通常用一般现在时。 主将从现原则Unless it rains, the

8、 game will be played.除非下雨，否则比赛将照常进行。=If it does not rain, the game will be played.如果天不下雨，比赛将照常进行。=If it rains, the game will not be played.如果天下雨，比赛将不能照常进行。Dont touch the machine unless the teacher allows you to.没有老师的允许，不要乱动机器。 Unless you try your best, you wont realize your dream.除非你尽力了，否则你将不会实现梦想。

9、You will be late unless you leave right now.你马上离开就不会迟到。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,你就不能及时赶到那儿。If you are not too tired, lets go out for a walk. =Lets go out for a walk unless you are too tir

10、ed. 2、unless引导的条件状语从句可放在句首或句尾，放在句首时常用逗号与主句隔开。如：Unless you work hard, you will fail.= You will fail unless you work hard.条件状语从句小结：1、引导词：常用if/unless，译作“假如，如果；除非”，表示“在某种条件下,会”。2、位置：可放在句首或句尾，放在句首时常用逗号与主句隔开。3、时态：在含有条件状语从句的复合句中，如果主句是一般将来时，从句要用一般现在时主将从现原则)，即遵循“主将从现”原则。 知识拓展：一、if引导的条件句有真实条件句和非真实条件句两种，上面所讲皆为

11、真实条件句。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 rains tomorrow, we wont go on a picnic. 如果明天下雨，我们就不去野餐。2.非真实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

12、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 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。3.if 既可引导条件状语从句，也可引导宾语从句。引导条件状语从句时译为：“如果-”，时态通常遵循“主将从现”原则。引导条件宾语从句时译为：“是否-”，时态要由主句的时态决定。如： I wonder if (是否)you

13、will come. If (如果)you come, I will give a good treat.二、条件状语从句中谓语动词的时态不可用将来时，只能用现在时态或过去时态表示将来时。如：If it doesnt rain tomorrow ,we will go to the zoo.If I had enough money , I would buy a car.如果我有足够的钱，我将买辆车。三、当条件状语从句的主语与主句一致或为it 或there且谓语动词含be动词时，从句中的主语和谓语可以一起省去。例如：Dont speak until spoken to.( 省you are)

14、I have no money. If any, I will lend you some. ( 省there is) If necessary, ring me up. (省 it is)With her help, I could do the experiment better. (If I had her help)巩固练习：. 用所给词的适当形式填空。1. If you _(feel) tired, you _ (have) to have a rest.2. Where _ he _(see) the film if he _(have) time?3. If there _(be

15、) fewer trees, there _( be) more pollution.4. He _(dress) more casually if he _( not work) on weekends.5.If I _(watch) the animals carefully, I _ (get) enough information for my report.6. Amy wont go camping unless she _(invite). . 单项选择。( )1. I wont take part in Julies birthday party _ I am invited.

16、 (2012济宁) A. unless B. after C. because D. if ( )2. If there is any change to the plan, I _ you as soon as possible. A. told B. have told C. tell D. will tell( )3. Mrs. Li, will you be angry _ your students dont obey the rules in class?A little. But I will stop them in a friendly way. （2015三亚）A. if

17、B. unless C. though( )4. There will be less pollution _ more people use public transportation. （2015江西）A. but B. though C. unless D. if( )5. I think you should complain, _, of course, you are happy with the situation. A. unless B. however C. until D. though( )6.-If you _careful enough, you may hurt

18、yourself. -Thanks. I will. A.dont B.arent C.dont be D.wont be( )7.My father _ me to the park if he _ free next Sunday. A.will take; is B.will take; will be C.takes; is D.takes; will be( )8.-Do you want to go swimming this afternoon? -Yes, if the weather _ warm. A.will be B.would be C.was D.is( )9.Yo

19、ull get worse _ you stay in bed for another day. A.if B.because C.so D.unless()10. Can students go online during lessons? They can _ it is for that lesson. A. if B. or C. so D. but( )11. There are fewer and fewer tigers in India. There will be no tigers left _ humans stop hunting them for their fur

20、and bones.A. unless B. if C. because D. since()12. (2019河池)We wonder if our parents will come to our graduating party next weekend. If they _，well be very glad.A. come B. comes C. are coming D. will come()13. (2019达州)Jeff, could you tell me if it _ tomorrow? If it _ tomorrow, I will stay at home. It

21、s reported that it will be sunny. Lets go camping on the Fenghuang mountain. A. rain; rain B. rains; rain C. will rain; rains D. will rain; will rain()14. (2019徐州)Helen was very rude to me. I refuse to speak to her again _ she says sorry.A. until B. if C. because D. since()15. (2019镇江)Is your WeChat account(账户) safe?Yes, even my father cant use it _ I tell him the password.A. when B. unless C. while D. if