1、ifif条件状语从句条件状语从句_ _语法语法What will I do if it is sunny this weekend?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 must .宾语从句宾语从句条件状语从句条件状语从句语法语法1：if作为宾语从句作为宾语从句的引导词，引导宾语从的引导词，引导宾语从句。（是
2、否）句。（是否）语法语法2：if（如果）引（如果）引导的条件状语从句导的条件状语从句宾语从句宾语从句 if 用于宾语从句中用于宾语从句中原句式原句式引导词引导词从句语序从句语序一般一般疑问句疑问句whether/if改为陈述句改为陈述句 语序语序由从属连词由从属连词whether, if 引导的宾语从句引导的宾语从句e.g. 1. I want to know _. （他是否跟我们一起去公园）（他是否跟我们一起去公园）2. Ask him _. （他是否能来）（他是否能来）3. I didnt know _.（是否要下雨）（是否要下雨） if (whether) he will go to t
3、he park with us whether (if) he can come whether it was going to rain or not当句末为当句末为or not时，引导词只能用时，引导词只能用whether而不能用而不能用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. 与与or not 连用只能用连用只能用whet
4、her介词后只能用介词后只能用whether与与to do 不定式连用只能用不定式连用只能用whether作主语只能用作主语只能用whetherIf 引导条件状语从句引导条件状语从句 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 on
5、e. 4. If the light _ (not come) on, _ (wait) for one minute.isbuygetdoesnt comewaitdont wait listenbuy祈使句祈使句+if条件状语从句条件状语从句 if条件状语从句，条件状语从句，+祈使句（从句后加逗号）祈使句（从句后加逗号）if条件状语从句要用一般现在时。条件状语从句要用一般现在时。句型结构句型结构时态时态If 条件状语从句（条件状语从句（1）What will you do if youre happy?vIf Im happy, I will _. vIf Im happy, I will
6、 _.vIf Im happy, I will _.vIf Im happy, I will _.clap my handsstamp my feetwink my eyesnod my headIf Im hungry,I will_. If Im tired, I will_. eat some foodhave a restIf Im ill,_. I will see a doctorIf Im late,_.I will say sorry If it rains tomorrow,I_.will watch TV at homeIf it _ tomorrow,_.Ill play
7、 basketballdoesnt rainI wont_.play basketballIf 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 playIf it is sunny this weekend, what wont you do ?If it is sunny this weekend, I _.If it is sunny this weeke
8、nd, I _.Wont stay at home wont watch television If you are free this weekend,what will you do ?If I am free ,sleepwatch TVplay computer gamespracticeif条件状语从句条件状语从句(2)句子特点：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。从句中可以加时间状语。2.当当if表示未来的条件时，主句中用一般将来时。表示未来的条件时，主句中用一般将来时。句型结构：句型结构：主句主句
9、+if条件状语从句条件状语从句 if条件状语从句，条件状语从句，+主句（从句后加逗号）主句（从句后加逗号）3.时态时态：if一般现在时，一般现在时，+主句一般将来时或主句一般将来时或（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。构成条件从句主句时态If一般现在时主语shall/will+动词原形例句If he comes,he will take us to the zoo.用法：1. 如果主句是一般将来时，从句则用一般现在时。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 wil
10、l stay at home. Ill go with you if you dont want to go alone（从句）. 2.如果主句含有如果主句含有must, may, can 等情态动词，从句也要用等情态动词，从句也要用一般现在时。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。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 f
11、inish 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，表示假设，表示将会发生和可能发生的事，或进行提醒警告。或进行提醒警告。If +句子（一般现在时），句子（一般现在时），+主句（主语主句（主语will/may/can) +动词）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 . 下列从句中的下列从句中的wil
12、l不是将来时助动词，而是情态动词。不是将来时助动词，而是情态动词。 翻译为翻译为“愿意愿意”。 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：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 s
13、ee him tomorrow ,give him this book . 如果你明天愿意去看他，给他这本书。vif条件句不一般条件句不一般,几个要点记心间。几个要点记心间。v条件句放在前条件句放在前,逗号要放句中间。逗号要放句中间。v条件句表可能条件句表可能,主句多用将来时；主句多用将来时；v条件句表事实条件句表事实,主句常用现在时。主句常用现在时。vif条件句有特点条件句有特点,现在时把将来替；现在时把将来替；v这个规则要牢记这个规则要牢记!if条件句歌诀条件句歌诀e.g. 1.If you dont get up early, you will be late for school .你
14、如你如果不早点起床，上学就会迟到。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。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。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。如果你想减肥，你必须少吃面包。5.If you heat ice it turn
15、s to water. (也可用也可用will turn)如果把冰加热，它就会化成水。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.arewill be3 If she_ (win) the prize ,we _(be) happy.winswill be4.If I _ (not,eat )so much ,I _(get) thinner.5.If you _(tell) them, they _ (not,believe) y
16、ou.dont eatwill gettellwont believe6 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 stayrainsdoesnt rainwill gowill playsunnybecomeswont
17、sendwill watchisdoesnt dowill do( ) 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.
18、 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. wa
19、nted 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 beexercisesBCABCD-Im always tired in the morning.-If you go to bed early, you wont be tired in the morning.Giving suggestions
20、:-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
21、 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
22、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
23、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 under
24、stand 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.if的用法的用法2.引导条件状语从句：引导条件状语从句：译为译
25、为“如果，假如如果，假如”(1) if从句从句+祈使句祈使句(2) if从句从句+主句（一般将来时）主句（一般将来时）1.引导宾语从句引导宾语从句：译为：译为“是否是否”，表示不确定的概，表示不确定的概念。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 .如果如果我是你，我会邀请他参加聚会。我是你，我会邀请他参加聚会。If he had hurried ,he co
26、uld have caught the train .如果他抓紧点，他会赶上火车的。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。如果我出国了，我会去美国。3.非真实条件句（虚拟语气）非真实条件句（虚拟语气）：表示不可实现的条件：表示不可实现的条件或根本不存在的条件。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。过去的一种假设。 If you have some problems in your life, what will you do?ProblemsMr Greens problem?If I have enough money,I will travel around the world行知天下：行知天下：P63专项练习。专项练习。Workbook:ex.1.2.
