if 引导的条件状语从句(Conditional sentences)be free tomorrow, play basketballIf I am free tomorrow, Ill play basketball.Ill play basketball if I am free tomorrow.doesnt rain tomorrow, play footballIf it doesnt rain tomorrow, Ill play football.Ill play football if it doesnt rain tomorrow.finish ones homework, go swimmingIf I finish my homework, Ill go swimming.Ill go swimming if I finish my homework.if引导的条件状语从句观察下列例句，总结if引导的条件状语从句的用法 。 【例句】1. If you stand in the rain, you get wet.2. You get wet if you stand in the rain. 3. If it doesnt rain tomorrow, I will plant some flowers in my garden.4. I will plant some flowers in my garden if it doesnt rain tomorrow.if 引导的条件状语从句 【总结】1. if意为 “_”， 引导_状语从句。当 表示条件成立就必然有某种结果（常用于客 观真理）时，主句和从句都用_时（ 例1、2）For example:1) If you stand in the rain, you get wet.2) You get wet if you stand in the rain. 如果条件一般现在当表示条件成立就可能有某种结果时，如果主句用_时，则从句用_时，简称“主将从现”（例3、4）。For example:3) If it doesnt rain tomorrow, I will plant some flowers in my garden.4) I will plant some flowers in my garden if it doesnt rain tomorrow.一般将来一般现在2. 当if引导的从句在主句之前时，_（用/不 用）逗号隔开两个句子（例1、3）；当主句在 从句之前，则_（用/不用）加逗号（例2、 4）。【例句】1) If you stand in the rain, you get wet.2) You get wet if you stand in the rain. 3) If it doesnt rain tomorrow, I will plant some flowers in my garden.4) I will plant some flowers in my garden if it doesnt rain tomorrow.用不用在 if 引导的条件状语从句中，还要注意前后时态一致的原则。Tips:Conditional sentencesIf you walk along the Bund，you will see many old buildings.The if-clause talks about a possible action.The main clause talks about the likely result.we can also put the if-clause after the main clause.You will see many old buildingsif you walk along the Bund.Main clauseif-clauseWork out the ruleThe verb in the if-clause is in (the simple present tense/the simple future tense).The verb in the main clause is in (the simple present tense/the simple future tense).A Williams mum is giving him advice about his problems. Match the half-sentences from the boxes to complete her advice for him. Williams problems 1. I sometimes bring the wrong books to school.If you check your timetable every night，you will know which books to bring.2. I was away from school today. I do not know what homework to do.If you call your friends, they will tell you what homework to do.3. I hate getting up. I always feel tired in the mornings.If you go to bed early, you will not feel tired in the mornings.4. I do not know what this word means.If you look it up in the dictionary, you will find out its meaning.B Carol is giving advice to Henry. What is she saying? Use the pictures and the words in brackets to help you._ the wheels round, they_ easily.(make/turn)If you makewill turn2.The seeds _in the soil.(grow/plant)will grow if you plant them3. _ another wing, it _.(put on/ fly)If you put onwill fly4. _ your coat, you _ so cold. (put on/not feel)If you put onwill not feel5. The meat _ in the fridge. (not go bad/put)will not go bad if you put it 6. You _your classes. (see clearly/wear)will see clearly if you wear“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。”一、判断下列句子的正误，如果有误，在后面的横线上更正。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/ If you light it, the candle burns.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 school if he will have time._正确will turn turnsvisits will visit/can visit will have has二、选择最佳答案填空。1. If he _ hard, he will get good grades. A. study B. studies C. will study D. studied2. If you _ water, it _ steam. A. boil, will become B. boil, becomes C. to boil, will become D. will boil, becomes BB3. Everyone must dress up. If you _,they wont let you in.A. dont B. wont C. cant D. mustnt4. Mary will go to Sanya if she _ a five-day trip.A. have B. had C. will have D. hasAD5.If it _ tomorrow, we _ hiking.A. dont rain, will go B. will rain, go C. doesnt rain, will go D. doesnt rain, go 6.He_ if it _ fine tomorrow.A. not leave, isnt B. doesnt leave, will not C. doesnt leave, isnt D. will not leave, isnt CD三、根据中文意思完成句子。1. 如果你不运动，你就会变胖。If you _ _ exercise, you _ _ _.2. 如果我早点完成作业，我就会早点睡。I _ _ to bed early if I _ my homework early.3. 如果植物得不到足够的水，它们就长不好。If plants _ _ enough water, they _ _ well.dont dowill get fatwill gofinishdont get dont grow四、用括号内所给单词的正确形式填空。 1. A fish _(die) if you _(take) it out of water for a long time. 2. Jack wants to know if they