1、单元语法聚焦三 祈使句,Unit 3 Safety,教材典句,Look at this yellow star, Brian and Jenny! 布莱恩、詹妮，看这颗黄色的星星！ 2. Let me get the ladder for you.让我给你拿把梯子。 3. Dont stand on chairs. 不要站在椅子上。,单元语法聚焦三,4. Be careful with scissors and knives!小心剪刀和刀子！ 5. Never smoke because of much pressure!永远不要因为压力大而吸烟！,单元语法聚焦三,语法探究,1. 定义祈使句是
2、英语中的基本句型之一，用来表达建议、命令、请 求、警告、劝告、禁止等语气。祈使句的主语一般为第 _人称，通常可以_。为了使语气更加客气或缓和，可在句前或句末加上_一词。,二,单元语法聚焦三,省略,please,2. 构成(1)祈使句的肯定形式一般以_动词或_动词原形开 始，也可以以动词let 开始。(2)祈使句的否定形式一般在句首加_或_。(3)以let开头的祈使句：肯定句：Let him come in.否定句：Dont let him come in.或Let him not come in.,单元语法聚焦三,实义,be,dont,never,(4)有些祈使句可用No开头，表示禁止。No
3、smoking, please. 请不要吸烟。No photos! 禁止拍照！,单元语法聚焦三,3. 拓展(1)祈使句的反意疑问句祈使句的反意疑问句，若陈述部分是否定句，则附加问句只能 用will you。若陈述部分是肯定句，附加问句既可用will you，也可 用wont you。lets开头的祈使句用于提出建议，包括对方，其附加问句用shall we。let us开头的祈使句表示征求对方许可，其附加问句用will you。,单元语法聚焦三,Dont do that again, will you? Go with me, will you/wont you? Lets go, shall
4、we? Let us take an exam, will you? (2)祈使句用于两个重要句型 “祈使句and表结果的陈述句”用来叙述肯定的条件。 “祈使句or表结果的陈述句”用来叙述否定的条件。,单元语法聚焦三,注意 这两个句型都可以改写为if引导的条件状语从句。 Work hard, and you will pass the exam. (If you work hard, you will pass the exam.) Work hard, or you will not pass the exam. (If you dont work hard, you will not pa
5、ss the exam.),单元语法聚焦三,实战演练,.单项选择 ( ) 1. 2017白银 Boys and girls，_ learning and have fun.Akeep Bto keep Ckeeping Dkept,A,单元语法聚焦三,( ) 2. _carefully, please! Look at the road sign. There is a school ahead.ADrive BTo driveCDriving DDrives,单元语法聚焦三,A,( ) 3. _ patient with him, please. He is only three years
6、 old. ADont BBe CIs DDoes,单元语法聚焦三,B,( ) 4. 2017渝北 _throwing those stones, please.AStop BStops CStopping DStopped,单元语法聚焦三,A,( ) 5. 2017安徽 Hold your dream，_ you might regret some day.Aand Bor Cbut Dso,单元语法聚焦三,B,( ) 6.2017滨州I want to be a teacher when I grow up.Work hard，_ your dream will come true.Aor
7、 Bbut Cthough Dand,单元语法聚焦三,D,. 按要求完成下列各题 1. 2017达州 This warning sign tells us not to pick flowers. (保持句 意基本不变)This warning sign says “_ _ flowers” 2. 2016天水 Tell him the truth at once, or he will be angry. (改为主 从 复合句)_ _ dont tell him the truth at once, he will be angry.,pick/No picking,单元语法聚焦三,Dont,If,you,3. 2017天水Let us go hiking, _ _？ (完成反意疑问句) 4. You should be relaxed. (改为祈使句)_ _， please. 5. Dont park here. (改为同义句)_ _！,will,单元语法聚焦三,Be,relaxed,No,parking,you,
