if条件状语从句语法.ppt

,If从句 条件状语从句,What will I do if it is sunny this weekend?,sleep,play computer games,go shopping,?,Part1:If 的用法,1.I want to know if he will go to park with us.,2. We will have a picnic if it doesnt rain.,3. If you boil water, it becomes steam.,4. If you feel tired, you must have a rest.,宾语从句,条件状语从句,巧计、速记,语法1：if作为宾语从句的引导词，引导宾语从句。（是否）,语法2：if（如果）引导的条件状语从句,宾语从句, if 用于宾语从句中,whether /if,改为陈述句 语序,由从属连词whether, if 引导的宾语从句,e.g. 1. I want to know _. （他是否跟我们一起去公园） 2. Ask him _. （他是否能来） 3. I didnt know _.（是否要下雨）,if (whether) he will go to the park with us,whether (if) he can come,whether it was going to rain or not,当句末为or not时，引导词只能用whether而不能用if.,If 与whether 的区别,I dont know _ he will come or not. I dont care of _ he is handsome. He wondered _ to stay here the next week. _ he will come is not decided.,与or not 连用只能用whether,介词后只能用whether,与to do 不定式连用只能用whether,作主语只能用whether,If 引导条件状语从句,Complete the sentences with the correct form of the words.,1.If you _(listen) to the music, _ (buy) a CD. 2. If he_ (be) late for school, _ (not wait ) for him. 3. If you _ (buy) a new camera, _ (get) a good one. 4. If the light _ (not come) on, _ (wait) for one minute.,is,buy,get,doesnt come,wait,dont wait,listen,buy,Revision,Revision,祈使句+if条件状语从句 if条件状语从句，+祈使句（从句后加逗号）,if条件状语从句要用一般现在时。,句型结构,时态,If 条件状语从句（1）,What will you do if youre happy?,If Im happy, I will _. If Im happy, I will _. If Im happy, I will _. If Im happy, I will _.,clap my hands,stamp my feet,wink my eyes,nod my head,If Im hungry, I will_.,If Im tired, I will_.,Look and say,eat some food,have a rest,If Im ill, _.,I will see a doctor,Look and say,If Im late, _.,I will say sorry,If it rains tomorrow, I_.,will watch TV at home,If it _ tomorrow, _.,Ill play basketball,doesnt rain,I wont_.,play basketball,If it is sunny this weekend, what will you do ?,If it is sunny this weekend, I _ football with my classmates.,If it is sunny this weekend, I_.,will play,If it is sunny this weekend, what wont you do ?,If it is sunny this weekend, I _.,If it is sunny this weekend, I _.,Wont stay at home,wont watch television,If you are free this weekend, what will you do ?,If I am free ,sleep watch TV play computer games,practice,grammar,if条件状语从句(2),句子特点： 1.if从句中用一般现在时，表示未来的一种条件，从句中可以加时间状语。 2.当if表示未来的条件时，主句中用一般将来时。句型结构： 主句+if条件状语从句 if条件状语从句，+主句（从句后加逗号）,3.时态：if一般现在时，+主句一般将来时或（can/ may /must +v.),If条件句：条件句用于陈述语气，表示假设的情况可能发生， 其中 if 是“如果”的意思。,用法： 1. 如果主句是一般将来时，从句则用一般现在时。 If it rains（从句）， I will stay at home. Ill go with you if you dont want to go alone（从句）. 2.如果主句含有must, may, can 等情态动词，从句也要用 一般现在时。 If you drive too fast, you may have an accident. You must stop if the traffic is red. 3. 如果主句是祈使句，从句同样要用一般现在时。 Dont go and play football if you dont finish your homework. Please call me if he comes next Sunday.,4.表示假设，表示将会发生和可能发生的事， 或进行提醒警告。 If +句子（一般现在时），+主句（主语will/may/can) +动词） If you finish your homework , you can go out and play. If I have enough money next year , I will go to travel . 下列从句中的will不是将来时助动词，而是情态动词。 翻译为“愿意”。 If you will excuse me,I really must go to bed . 如果你能原谅我的话，我真的要睡觉了。 If you will wait a minute ,Ill go and tell my mother that you are here . 如果你愿意等一会的话，我去告诉我妈妈你来了。,试比较下列句子： If you see him tomorrow ,give him this book . 如果你明天去看他，给他这本书。 If you will see him tomorrow ,give him this book . 如果你明天愿意去看他，给他这本书。,if条件句不一般,几个要点记心间。 条件句放在前,逗号要放句中间。 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。 if条件句有特点,现在时把将来替； 这个规则要牢记!,if条件句歌诀,e.g. 1.If you dont get up early, you will be late for school .你如果不早点起床，上学就会迟到。 2. If I play games on it , it will go wrong . 如果我用它玩游戏，它就会坏掉。,3. If you finish the homework， you can go home 如果你作业做完了就可以回家了。,4. If you want to lose weight you must/should eat less bread. 如果你想减肥，你必须少吃面包。,5.If you heat ice it turns to water. (也可用will turn) 如果把冰加热，它就会化成水。,1.If he_ (not, do it ), I_(do) it.,2.If you _ (be) late for school ,my teacher _(be) angry.,are,will be,3 If she_ (win) the prize ,we _(be) happy.,wins,will be,4.If I _ (not,eat )so much ,I _(get) thinner.,5.If you _(tell) them, they _ (not,believe) you.,dont eat,will get,tell,wont believe,6 I _(stay) at home,If it _( rain).,7.If it _(not,rain) ,I _( go) out.,8. we _(play) football, If it is _(sun) .,9.If she _(become) a star ,her parents _ (not,send) her away,10.He _(watch) TV ,if he _(be) free.,will stay,rains,doesnt rain,will go,will play,sunny,becomes,wont send,will watch,is,doesnt do,will do,Exercise Time,( ) 5. Mike wants to know if _ a picnic tomorrow. Yes. But if it _, well visit the museum instead. A. you have/ will rain B. you will have/ will rain C. you will have/ rains D. will you have/ rains ( ) 6. I really dont know if she _ it when she _. A. finds/ arrives B. finds/ will arrive C. will find/ will arrive D. will find/ arrives,（ ）4. The volleyball match will be put off (推迟） if it _. A. will rain B. rains C. rained D. is raining,（ ）1. Be careful, if you_ want to make mistakes. A. wont B. dont C. didnt D. not （ ）2. Work hard if you _ to get a good mark. A. wanted B. wanting C. want D. will want （ ）3. -I want to know if you_ to the party tomorrow. - I will if I_ free. A. will come; am B. come; am C. will come; will be D. come; will be,exercises,B,C,A,B,C,D,-Im always tired in the morning.,-If you go to bed early, you wont be tired in the morning.,Giving suggestions:,-I get thirsty when I run.,-If you take some water with you, you wont get thirsty when you run.,I worry so much about my schoolwork.,-If you always work hard, you wont worry about your schoolwork.,You should work hard!,Unit 3 activity 1 Rewrite the sentences with if:,Listen in class, or you wont understand what to do.,If you dont listen in class, you wont understand what to do.,1) Eat some breakfast, or youll get hungry at school. 2) Hurry up! Well be late! 3) Read the instructions carefully. Then youll know what to do.,If you dont eat some breakfast, youll get hungry at school.,If you dont hurry up, well be late.,If you read the instructions carefully, youll know what to do.,Activity2.Complete the sentences, I want to get high scores. If _(work hard/ do well),you work hard, you will do well.,1.-how can I remember my friends birthdays? -If_ (keep a note in your diary / not forget). 2.-Its late, but I dont want to go to sleep. -If _ (not get enough sleep/ feel tired at school).,you keep a note in your diary, you wont forget.,you dont get enough sleep, youll feel tired at school.,3.-I dont like speaking English outside the classroom. -If_ (not practice / not improve). 4.-Should I tell my teacher I dont understand the homework? -If_ (not tell her / she not able to help you). 5.-Is it OK if I watch TV for six hours? -If_ (you watch too much / eyes hurt).,you dont practice, you wont improve.,you dont tell her, she wont be able to help you.,you watch too much TV, your eyes will hurt.,summary,if的用法,2.引导条件状语从句：译为“如果，假如” (1) if从句+祈使句 (2) if从句+主句（一般将来时）,1.引导宾语从句：译为“是否”，表示不确定的概念。,I dont know if your father can come together . Can you tell me if miss your parents ?,e.g. 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。 If he had hurried ,he could have caught the train .如果他抓紧点，他会赶上火车的。 If I were to go abroad ,I would go to America. 如果我出国了，我会去美国。,3.非真实条件句（虚拟语气）：表示不可实现的条件或根本不存在的条件。 从句多用一般过去时或过去完成时，表示对现在或过去的一种假设。,If you have some problems in your life, what will you do?,Problems,Mr Greens problem?,If I have enough money, I will travel around the world,行知天下：P63专项练习。 Workbook:ex.1.2.,Homework:,Thanks for listening. Goodbye.,