if条件状语从句-课件.ppt

Language,If sentences,If 引导的条件状语从句,If you cool water, it turns into ice. ,if clause 从句,main clause 主句,If sentences,if 引导的条件状语从句,1. If you heat metal, it melts. 如果把金属加热，它就会融化。 2.Water turns into ice if you cool it. 如果你冷却水，它就会变成冰。,if clause从句,main clause主句,从句,主句,从句,主句,从句在主句前时，_ （用/不用）逗号隔开 当主句在前时，则_ （用/不用）逗号,不用,用,If you drop a glass, it breaks.,If you heat ice, it melts.,If you stand in the rain, you get wet.,主句和从句都用_(时态) 因为if引导的条件句说的是_,一般现在时,客观事实/普遍现象,Actions with definite results,读下列例句，试着自己总结if 的用法： 1. If you heat metal, it melts. 如果把金属加热，它就会融化。 2.Water turns into ice if you cool it. 如果你冷却水，它就会变成冰。 3.If you stand in the rain, you get wet. 如果你站在雨里，就会淋湿。 4.If you drop a glass, it breaks. 如果你把玻璃杯掉在地上，它就会碎。,由例句我们可以知道： 如果if引导的条件句谈论的是一种_ 时，主句谓语动词便不用shall/will+动词原形，而直接用_时的动词形式。,真理/ 客观事实,一般现在,Actions with Definite Results,Water _ (turn) into ice if you _ (cool) it. If you _ (stand) in the rain, you _ (get) wet.,turns,cool,stand,get,- b - d - g - a - h - c - f - e,Exercise A1,1. If you _water. 2. A balloon _ it. 3. If you _water. 4. Metal _it. 5. Wood _water. 6. A glass_ it.,heat ice, it turns into,bursts if you stick a pin into,cool steam, it turns into,melts if you heat,floats if you put it into,breaks if you drop,Exercise A2,Actions with possible results,读下列例句，总结if 的用法： 1.If he runs, hell get there in time. 如果他跑步去，就会及时赶到那。 2.He will help you if you ask him. 如果你请他帮忙，他会帮你的。 3.If you fail in the exam, you will let him down. 如果你考试失败了，你会让他失望的 4.If you get up late, you will be late for school. 如果你起床晚了，上课就会迟到。,由例句我们可以知道： 在if 引导的条件状语从句中，如果从句谈论的是一个有可能发生的事实以其产生的相关结果，从句用_, 主句用_.,一般现在时态,一般将来时态,(主将从现),I _(stay) at home if it _ (rain) tomorrow. If he _ (not come), I _ (go) swimming alone.,will stay,rains,doesnt come,will go,Actions with Possible Results,If you get up late, you will be late for school.,Look and say,get up late,late for school,If the telephone rings, I will answer it.,Look and say,ring,answer,If I have a lot of money, I will buy a big house.,Look and say,a lot of money,a big house,hard-working,If she is hard-working, she will get good grades.,get good grades,Look and say,go fishing .,If it is sunny this Sunday, Ill go fishing .,Look and say,sunny this Sunday,P105 B,William has five problems Give him some advice from column A and B 1 I sometimes forget to take the right book to school. If you check your timetable every night , youll know which books to take.,一、判断正误，如果有误，请更正 1. If you will do more exercise this summer, you will be very fit. 2. The candle burns , if you light it.,will do do,把逗号去掉,3. I will build many schools for the poor children if I win a billion dollars. 4. If you freeze water, it will turn into ice. 5. My uncle visits the museum if he will have time.,正确,will turn turns,visits will visit, will have has,If 的两个意思:,If:,“如果” “是否”,引导条件状语从句,引导宾语从句,I dont know if he will come tomorrow.,I will go to the cinema if it doesnt rain.,主现从现/主将从现,if可用将来时,Betty will visit the History Museum if it _ (rain) tomorrow. Ben wants to know if it_ (be) fine tomorrow.,If 引导的条件状语从句不用将来时，意思为“如果”。 If 引导的宾语从句可以用将来时，意思为“是否”。,doesnt rain,will be,是否,如果,Exercises :,He will help me with my maths if he _ free. A was B will be C would be D is I dont know_ he will come tomorrow._ he comes, Ill tell you. A if; Whether B whether; Whether C if; That D if ; If 3. Please tell her my telephone number if she _ (want) to know.,wants,D,D,4. Will you come and stay with us for a while if you _ (finish) doing your homework? Wang doesnt know if there _ (be) an English evening next week. Mike asked me if we _ (ask) any questions the next class. We are going for picnic tomorrow. Ill call Wendy to make sure_. A why to start B when to start C what to start D which to start,would ask,finish,will be,B,8. - Would you please tell me_ next? - Think it over. Youll find a good way. A when to do B how to do C what to do D where to do 9. I dont know if my uncle _. If he _, I will be very happy. A comes; will come B will come; will come C comes; comes D will come; comes 10. Either you or I _ going to Shanghai. Only one person may go there. A are B were C am D was,C,D,C,( ) 11. If it _ sunny tomorrow, I _ boating. A. is go B. will be, go C. is, will go D. will be, will go ( ) 12. - what will you do if it _ tomorrow, -Ill stay at home and watch TV. A. rain B. rains C. will rain D. is raining,C,B,( ) 13. If he _, I _ him the time. A. comes, tell B. will come, will tell C. comes, will tell D. will come, tell ( ) 14. If it _, it _cold. A. snows, will be B. snows, is C. will snow, will be D. will snow, is ( )1 5. If you _a stone into water, it _. A. put, sinks B. put, will sink C. will put, sinks D. will put, will sink,C,B,A,11. He_ (help) me with my maths if he _ (be) free. 12. I dont know if Jim _ tomorrow. If he _, I will be very glad. (come) 13. _ (tell) her my telephone number if she _(want) to know. 14. If it _ (be) sunny tomorrow, I _ (go) boating. 15. If you _ (boil) water, it _ (turn) into steam. 16. You can _ (travel) around the world if you _ (have) money.,will help,is,will come,comes,Tell,wants,is,will go,boil,turns,travel,have,Translate the following sentences: 1. 如果你请他帮忙,他会帮你的。 If you ask him, he will help you. 2. 如果你考试不及格,你会让他失望的。 If you fail in the exam, you will let him down. 3. 如果你作业做完了就可以回家了。 If you have finished the homework，you can go home 4. 如果熊陷入危险，它们就攻击人。 If bears are in danger, they attack people. 5. 如果我早早地到那里，我就可以快点看病。 If I get there early，I can see the doctor quickly.,翻译下面句子。 1.如果明天不下雨的话，我就和同学们去动物园。 2. 如果周六你去购物的话，我就去。,If it doesnt rain tomorrow, I will go to the zoo with my classmates.,I will go shopping on Saturday if you go.,Test yourself,3.如果可能的话，我就去火车站接你。 4.如果你想减肥，就锻炼身体吧。,If possible, Ill meet you at the railway station.,Take some exercise if you want to be thinner/ lose weight.,Test yourself,