1、单元语法小专题(Grammar Focus)语法精讲if 引导的条件状语从句的用法条件状语从句通常由连词 if 引导，意为“如果、假如” ，表示在某种条件下，很可能会发生某种事情。来源:学优高考网1if 条件状语从句的位置在 if 引导的条件状语从句中，if 条件句位置灵活，可直接放在主句后面，若 if 条件句放句首， 从句后面要加逗号，和主句隔开。如：If I have time tomorrow，Ill go to the countryside with my friends. Ill go to the countryside with my friends if I have tim
2、e.如果我明天有时间，我将和我的朋友们去乡下。2if 条件状语从句的时态搭配来源:学优高考网 gkstkif 引导条件状语从句，主句用一般将来时，从句则用一般现在时。如：If it rains tomorrow，I wont climb the hills.如果明天下雨，我就不爬山。温馨提示：在 if 引导的条件状语从句中，有时根据句意的需要主句可能用到情态动词。如：If you finish your homework，you can watch TV. 如果你完成了家庭作业，你可以看电视。3if 引导的条件状语从句与 if 引导的宾语从句的区别if 引导的条件状语从句，if 意为“如果”
3、，主句用一般将来时，从句则用一般现在时；if 引导宾语从句时，if 意为“是否” ， 相当于 whether，时态需根据语境确定。如：I dont know if it will rain tomorrow.我不知道明天是否会下雨。if 条件状语从句用法歌诀：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。4与其他句式之间的句型转换(1)借助“祈使句and (or)一般将来时的句子”这一句型来转换。and 在句意上表示顺承关系，or 表示转折关系。如：If you get up early，youll get
4、there on time. Get up early，and youll get there on time.来源:gkstk.ComGet up early， or you wont get there on time.早点起床，你就会准时到那里。(2)借助介词 without 或 with 来转换条件状语从句。如：If there is no water，fish will die.Fish will die without water.如果没有水，鱼就会死。If you help me，Ill finish the work soon. With your help，Ill finis
5、h the work soon.如果你帮助我，我就会快点完成工作。语法精练.用括号内所给单词的适当形式填空。1I _(buy) you a computer if you get good grades.2We _(not go) there if he doesnt agree.3You will win the match if you _(practice) hard.4Please call me if you _(have) any questions.5You may go swimming if you _(finish) your homework.单项选择。( )6.Do y
6、ou know when he will come back tomorrow?Sorry，I dont know. When he _ back，Ill tell you.Acomes Bwill come Ccome Dmay come ( )7.Mary will go to Sanya if she _ a fiveday trip.Ahave Bhad Cwill have D has( )8.What will you do if you _ to the party without invitation?Ago Bwent Cgoing Dwill go ( )9.If I ea
7、t too much food， I _ too fat.Aam Bwas Cwill Dwill be( )10.Ill give the book to him if he _ here next Sunday.Awill come Bcomes Cis coming Dcame.改为同义句，每空一词。11Study hard，or you wont pass the exam.If you study hard，you _ _ the exam.12Take a taxi，and youll catch the train._ you _ a taxi，youll catch the t
8、rain.13If you dont help me，I cant catch up with the others.来源:gkstk.ComI cant catch up with the others _ _ _.来源:学优高考网 gkstk14Use your head and youll have a good idea._ you _ your head，_ have a good idea.15If you are late，the teacher will be angry._ _ late，_ the teacher will be angry.单元语法小专题(Grammar Focus).1.will buy 2.wont go 3.practice 4.have 5.finish.610 ADADB.11.will pass 12.If；take 13.without your help 14.If；use；youll 15.Dont be；or
