1、If引导的条件状语从句引导的条件状语从句Grammar重点、难点1.if 引导的条件状语从句的概念和结构2. 含有if引导的条件状语从句的复合句中主从句的时态。3. If引导的宾语从句与条件状语从句的区别。 考情分析通常在单项选择、完形填空或补全、完成句子等题型中考查，分值约34分。IfIgetupat7:00,Iwillbelate.IfIamlate,theteacherwillbeangrywithme.Iftheteacherisangrywithme,Iwillbesad.If 引导条件状语从句 一，定义：一，定义：if “如果如果, 假如假如” 它引导的句子表示某事发生它引导的句子
2、表示某事发生所需的条件，即所需的条件，即“在在条件下，某事才能发生条件下，某事才能发生”，在句子中充，在句子中充当状语，因此称之为条件状语从句当状语，因此称之为条件状语从句。IfIf you get up late, you you get up late, you will be will be late for schoollate for school. .Look and say例句例句If I have enough money, I will travel around the world ：二二.if引导的条件状语从句位置引导的条件状语从句位置从句从句主句主句I I willwi
3、ll travel around the world if I have travel around the world if I have enough money .enough money . .原句可改为：原句可改为：if引导的条件状语从句既可以放在句子前，引导的条件状语从句既可以放在句子前，也可以放在句子后。也可以放在句子后。从句位于主句之前时，常用逗号将其与主句隔开从句位于主句之前时，常用逗号将其与主句隔开。结构结构：_if Im ill. IwillseeadoctorLookandsayIf Im late,_.Iwillbepunished.位置：从句可放在主句之前或之后，但
4、是放位置：从句可放在主句之前或之后，但是放在主句之前须有逗号隔开在主句之前须有逗号隔开例如：例如：Wewillgototheparkifit_(rain)tomorrow.三，三，含含if条件状语从句的主从复条件状语从句的主从复合句的时态合句的时态1.if条件状语从句中，主句用一般将来条件状语从句中，主句用一般将来时，从句用时，从句用_表示将来表示将来_原则。原则。doesnt主将从现主将从现rain一般现在时一般现在时It is going to rain tomorrow.Iwillstayathome. Ifit_tomorrow,I_athome. rainswillstayHewon
5、tstudyhard.Hewillfailintheexam.“Ifhe_studyhard.He_intheexam.”doesntwillfailIf I have much money, I willtravelallovertheworld.buylotsofdeliciousfood.2.if条件状语从句中，如果主句有条件状语从句中，如果主句有must，can，may等情态动词，从等情态动词，从句用句用_。 例如：例如：Youmuststopifthetrafficlight_(be)red.is一般现在时一般现在时“主情从现主情从现”IfIf you feel hungry, yo
6、uyou feel hungry, you shouldshould eat something.eat something.If you feel tired, , youyou must have a resthave a rest.例如：例如：DontwaitformeifI_(be)late.3.if条件状语从句中，主句是祈使句，条件状语从句中，主句是祈使句，从句用从句用_表示将来。表示将来。_原则。原则。am主祈从现主祈从现一般现在时一般现在时if 引导的条件状语从句时态u主将从现u祈使句u情态动词I will sing a song if I am happy.Dont cross
7、 the road if the light is redYou must stop if the traffic light is red.2.Ifit_(be)coldtomorrow,Iwillwearmysweater.3.Hecangohomeifhe_(finish)hishomework.finishes1.Putupyourhandsifyou_(have)anyquestions.haveis注意事项注意事项1.在在if引导的条件状语从句中，当主句是一般将引导的条件状语从句中，当主句是一般将来时时，不能够使用来时时，不能够使用begoingto结构，而要用结构，而要用will
8、。例如：例如：IllhelpyouwithyourEnglishifIamfreetomorrow.如果明天我有空，我会帮你学英如果明天我有空，我会帮你学英语。语。2.在在if引导的条件状语从句中不能够使用引导的条件状语从句中不能够使用some，而要用而要用any。例如：例如：Ifyouhaveanyquestionstoask,pleasecometomyoffice.如果你有问题要问的如果你有问题要问的话，请到我办公室来。话，请到我办公室来。 四四、if的两面性的两面性 if引导条件状语从句时意为引导条件状语从句时意为“如果如果”，如果引导宾语从句则意为，如果引导宾语从句则意为“是否是否”
9、，放在谓语动词之后。请比较：放在谓语动词之后。请比较： 1) We will go out if it is fine tomorrow. 2) I dont know if the train has arrived. A jokeAmanlikedagirlverymuchandasked if the girl could marry him.Butthegirldidntagree.Shesaid,“ifthereisonlyonemanleft,Iwillmarryyou.” Part1:If 的用法 1.I want to know if he will go to a park
10、with us.2. We will have a picnic if it doesnt rain.3. Can you tell me if there will be a concert tomorrow? 4. Ifyoufeeltired,you,you must haveahavearestrest.宾语从句条件状语从句条件状语从句宾语从句Betty will visit the History Museum if it Betty will visit the History Museum if it _ (rain) tomorrow._ (rain) tomorrow.Ben
11、 wants to know if it_ Ben wants to know if it_ (be) fine tomorrow.(be) fine tomorrow.If 引导的条件状语从句应遵从主从句是时态相呼应原则，不用一般将来时If 引导的宾语从句主句是一般现在时态，if引导的宾从该用什么时态就用什么时态。doesntrainwillbe是否是否如如果果Exercises : 1.He will help me with my maths if he _ free. A was B will be C would be D is2. Please tell her my teleph
12、one number if she _ (want) to know.wantsDD3. 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; comesD( ) 4. If it _ sunny tomorrow, I _ boating. A. is go B. will be, go C. is, will go D. will be, will go ( ) 5. - what will
13、 you do if it _ tomorrow, -Ill stay at home and watch TV. A. rain B. rains C. will rain D. is raining CB if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;条件句条件句,放在前放在前,逗号要放句中间。逗号要放句中间。条件句表可能，条件句表可能，主将从现不一般；主将从现不一般；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If还有还有“是否是否”意意,宾语从句放后边宾语从句放后边summary if will she, call me, I, tell her about
14、itIf she calls me, I will tell her about it. he ,come, next weekend, I ,tell you If he comes next weekend, I will tell you. not rain , go hiking ,this afternoon If it doesnt rain, I will go hiking this afternoon. it, be sunny, she, fly a kiteIf it is sunny, she will fly a kite. he,have free time, go to Shanghai , If he has free time, he will go to Shanghai. she, study hard, she, get good gradesIf she studies hard, she will get good grades.
