if引導(dǎo)的條件狀語從句知識(shí)點(diǎn)及練習(xí)題

1、if引導(dǎo)的條件狀語從句（一）定義 if引導(dǎo)的句子在復(fù)合句中表示條件，假如if從句的動(dòng)作發(fā)生，主句的動(dòng)作就（不）會(huì) 發(fā)生，因此稱為條件狀語從句。（二）位置 if 引導(dǎo)的條件狀語從句位置靈活，可直接放在主句后面，也可以放在句首。放在句首 時(shí)，從句后面要用逗號(hào)和主句隔開。 If I have enough money, I will travel around the world. I will travel around the world if I have enough money.（三）用法（1）當(dāng)主句是一般將來時(shí)時(shí)，從句用一般現(xiàn)在時(shí)。（主將從現(xiàn)）構(gòu)成條件從句主句時(shí)態(tài)If+一般現(xiàn)在時(shí)主句+s

2、hall/will+動(dòng)詞原形例句 If it rains tomorrow, well stay at home（2）當(dāng)主句是祈使句時(shí)，從句也用一般現(xiàn)在時(shí)。 Work hard, and youll pass the exam easily. 努力學(xué)習(xí)，你將很容易通過考試。 If you work hard, youll pass the exam easily. Hurry up, or youll miss the train. 快點(diǎn)兒，否則你就趕不上火車了。 If you dont hurry up, youll miss the train. （3）當(dāng)主句含有情態(tài)動(dòng)詞時(shí)，if引導(dǎo)的條件

3、狀語從句通常用一般現(xiàn)在時(shí)。 We must study hard if we want to pass the final exam. 如果想通過期末考試，我們必須努力學(xué)習(xí)。（4）用含介詞with或without的介詞短語轉(zhuǎn)換。 If you help me, I'll finish my job soon. With your help, I'll finish my job soon. 如果你幫我，我將很快完成我的工作。 If there is no water, fish cant live. Fish cant live without water. 離開水，魚不能生存

4、。 （四）if引導(dǎo)的條件狀語從句及if引導(dǎo)的賓語從句的區(qū)別 if引導(dǎo)賓語從句時(shí)表示“是否”，位于及物動(dòng)詞之后； if引導(dǎo)的條件狀語從句時(shí)表示“假如，如果”，位于句首或句中。 I don't know if he will come tomorrow. If he comes, I'll call you.練習(xí)一、選擇題1. _ you don't go to bed earlier, you will feel tired in the morning. A. Unless B. If C. Though D. Until2. Why not look up the n

5、ew word in a dictionary _ you don't know it? A. if B. that C. though D. whether3. Talk to your teacher and you will get help _ you have a problem. A. unless B. if. C. until D. so4. I won't go to tomorrow's party _ I'm invited. A. if B. unless C. when5. The children will climb the hil

6、l if it _ tomorrow. A. won't rain B.didn't rain C. isn't raining D. doesn't rain6. We wonder if our teachers _ to our graduating party next weekend. If they_, we'll be very happy. A. will come; will come B. come; will come C. will come; come D. come; come二、翻譯句子。1. 如果明天下雨，我們將在家看電視。 We'll stay at home watching TV if it _ （rain）tomorrow.2. 如果她早點(diǎn)起床，就有時(shí)間在家里吃早餐. If she _ _ a little earlier, she ll have time to eat breakfast at home. 3. 如果你參加聚會(huì)，你將會(huì)過得很開心。 If you _ the party, you _ _ a great time.4. 如果你經(jīng)常聽英文歌，你將會(huì)喜歡英語。 If you often _ _