1、 If 条件状语从句提纲一、条件状语从句的概念一句话中的时间、地点、原因、方式、条件等就是句子的状语，如果句中的条件是一个句子，这个句子就叫条件状语从句。例如：If I get up early tomorrow morning, I will call you. 如果明天早上我起的早，我会给你打电话的。句中“明天早上早起” 这句话，是“ 我给你打电话”的一个条件，所以这里的 “ If I get up early”就叫条件状语从句，而“I will call you” 就是这句话的主句。条件状语从句的引导词常见的有：if (如果) ，unless（除非） ，as long as(只要)等，目
2、前我们最常见的是 if 引导的条件状语从句。二、条件状语从句的位置If 引导的条件状语从句可以放在主句前，也可以放在主句后。例如：If bears are in danger, they attack people. = They attack people if bears are in danger.熊在危险时会攻击人。三、条件状语从句中的时态条件状语从句的主句可以是祈使句，也可是其他句式。条件状语从句一定要特别注意时态的用法，下面我们来总结一下：1. 当主句的谓语是一般将来时时，从句谓语用一般现在时(表达将来时)If it rains tomorrow, we will not go t
3、o the zoo.如果明天下雨，我们将不回去动物园。2. 主句的谓语是“情态动词+动词原形时，从句谓语用一般现在时（表达将来时）I can buy you an MP4 if you get good marks in the final examination.如果期末考试你取得好成绩，我就给你买 MP4。3. 主句是祈使句时，从句谓语用一般现在时（表达将来时）If you want to turn on the recorder, press the blue button.如果你想要启动刻录机的话，按蓝色按钮。注意：以上三种情况中，从句本应该使用将来时的，但因为用于条件状语从句中，就用
4、一般现在时来表达将来时的含义了，被称为“主将从现”。这是条件状语从句中时态的特殊用法，并且这个规则也适用于时间状语从句和让步状语从句，这是我们以后会学到的。4. 主句谓语是过去的时态时，从句谓语也要用过去的时态。She said she wouldnt go to the Great Wall, if it rained tomorrow.她说如果明天下雨她就不去长城了。现在相信你已经很清楚的了解 if 引导的条件状语从句时态的判断了吧？别忘了，我们本单元主要学习的是主句是祈使句的时间状语从句。【精练】根据汉语完成英语句子，每空词数不限。1. 如果下周末下雪，这些学生将不去野餐。If it n
5、ext weekend, the students . 2. 如果他获奖了，他的父母将会很高兴。His parents happy if he the prize. 3. 如果我们不会做，我们将向老师求助。We our teacher for help if we it. 4. 我今天将乘公共汽车上学。 如果这样的话，你就不会迟到了。 Ill take a bus to school today. If you , you school. 【点拨】在 if 引导的条件状语从句中，if 从句是实现主句动作的条件，可以加表示将来的时间状语，但通常用一般现在时，而主句用一般将来时。当主句是一般将来时
6、时，if 从句也可用情态动词。为避免重复，条件从句中常用 do 来替代上文所提到的动作。【拓展】if 还可表示“是否 ”，相当于 whether，用于引导宾语从句，此时宾语从句的时态根据实际情况确定。如：I dont know if he will come tomorrow. If he comes, I will tell you. 我不知道他明天是否会来。如果他来，我就告诉你。If 条件状语从句（1）句型结构： 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）时态： if 条件状语从句要用一般现在时。条件状语从句专项练习 一选择正确答案。 ( )1. It was
7、 raining heavily we got to Paris. A. while B. if C. when ( )2. I dont know if tomorrow. A. it doesnt rain B. the rain will stops C. it will rain ( )3 . The volleyball match will be put off(推迟) if it A. will rain B. rains C. rained ( )4. Difficulties are nothing if we not afraid of them A. will B. sh
8、all C. are ( )5. We Beijing tomorrow if it doesnt rain. A. are going to B. would C. will go( )6. Ill go to meet you，if I free then. A. would be B. will be C. am ( )7. Be careful, if you want to make mistakes. A. wont B. dont C. didnt ( )8. Work hard if you to get a good mark. A. wanted B. wanting C.
9、 want ( )9. 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 ( )10. There is going to sports meeting next week. If it , well have to cancel it A. be; will rain B. have; will rain C. be; rains ( )11. If he , I go swimming alone. A. does
10、nt come, will go B. wont come; will go C. will come; wont go ( )12. If you a chance to study in a foreign country, just take it. A. getting B. get C. will get ( )13. Frank a film if hes free next Saturday. A. see B. saw C. will see 2用所给词的适当形式填空。 1. Dont go out tomorrow if it _ _ (rain) . 2. 2. I don
11、t know if he _ _(come) tomorrow. 3. 3. If you the telephone _ _(ring) , answer it. 三 按要求转换句型。 4. You want to record(记录). You should press(按) the red button(按钮).(合并成含 if 的条件句) _ 5. Which bus should I take? I want to the bank. (合并成含 if 的条件句) _ 6. I wil do it. I can do it. (合并成含 if 条件句的省略句) 7. I will g
12、o swimming. It wont be cold tomorrow. (合并成含 if 的条件句) 四、用所给词的适当形式填空。1.If you _(feel) tired, you _ (have) to have a rest.2. Where _ he _(see) the film if he _(have) time?3. If there _(be) fewer trees, there _( be) more pollution.4. He _(dress) more casually if he _( not work) on weekends.5. If Marcia
13、_(live) alone, she _( keep) a pet parrot.6. Lana _ buy) a new dress if the old one _(be) out of style.7.The twins _(fight) if they_(argue).8. I _(have) a bake sale if I _(need) money for education.9. Peter _( send) me a beautiful souvenir if he _(tour) Spain.10. If Mr Green _ (say) I am hard- workin
14、g, my parents _( feel) glad.11.I _(go) to the beach if it_ ( not rain) this week.12. _they _( have) a match if the P.E. teacher _(be) busy?13.He _(write) a letter to his grandparents if he _(get) his report card this week. 14. If she _(get) up late, she _ ( not catch) the early bus.15. Peter _(major) in English if he _(pass) the exams in Peking University.
