Unit6语法讲义 2023-2024学年沪教牛津版英语七年级上册

七上U6语法-if条件状语从句 一．If条件状语从句的概念 If条件状语从句，表示主句动作发生的条件,由连接词if引导,if引导的条件状语从句表示：假如从句的动作发生，主句中的动作才能发生，“如果......将会......”。 二、If条件状语从句的构成: 1. If you ask him, he will help you． ↓ ↓ （从句） （主句） 2. Print the photo if you like it. 如果喜欢这张照片就把他打印出来。 ↓ ↓ （主句） （从句） ▲If：从属连词，意思是：“如果，假如，倘若” 同步练习：判断主句和从句： 1. You will keep healthy if you do more exercise. 2. If you do more exercise, you will keep healthy. 三、If从句的位置： if 引导的条件状语从句既可以放在主句前，也可以放在主句后。从句位于主句之前时，常用逗号与其隔开。 Eg：If you ask him, he will help you. =He will help you if you ask him. 练习：My sister will be very happy if our uncle comes next week. 同义句________________________________________________ 四、If从句的时态： 1.用if条件句表达客观真理或普通现象，主，从句时态均用一般现在时。 Eg: If you freeze water, it turns into ice. A fish dies if you take it out of water. 2.用if 条件句表示将来可能发生的事情，主句用一般将来时，而if从句用一般现在时表示将来的时间，即主将从现。 Eg: If I like the house, I will buy it. I will tell her if I see her. 3.主句中的will也可以用情态动词can, may 或might等代替。 Eg: If they are friendly，I might invite them to the party. If we hurry now, we can stop for coffee later. 注意：在if条件句中，主句部分只能使用动词will的一般将来时，不能使用be going to结构 需要背诵的重点语法：If引导的条件状语从句，主将从现，意思是主句用一般将来时，if从句用一般现在时 语法专项训练 （一） 一、单项选择 1. If it ________ snowing, we can go out. A. stop B. stops C. will stop D. stopped 2. If you heat the water. It ________ water vapour(蒸汽). A. won't become B. becomes C. become D. don’t become 3. We ________ great fun if we ________ to the beach. A. will have; go B. have; will go C. are having; will go D. had; went 4. They ________ to the cinema if it ________ tomorrow. A. don't go; rain B. won't go; will C. won’t go; rains D. aren't going; will rain 5. If it ________, he ________ a coat. A. is cool; will wear B. will be cool; wears C. will be cool; will wear D. is cool; wear 6. He ________ very busy this week, but he ________ free next week. A. will be; is B. is; is C. will be; will be D. is; will be 7. The food will go bad if you _