(
课件网) Grammar Focus Read the sentences. Do the verbs in red need to change forms Why Walk in the hallways. Don’t run. Be polite and treat one another with respect. Don't litter./You mustn't litter. You can't litter. Can we bring our phones to class No, we can’t, but we keep them in our lockers. Can we eat snacks in class No, we can’t eat in class,but we have to eat in the dining hall. 英语句子按照用途可分为陈述句、疑问句、祈使句和感叹句四类。 1.祈使句一般用来表示请求、命令、劝说、号召、警告等。 2.祈使句的主语一般是第二人称you，但往往省略。 3.祈使句的肯定式以动词原形开头，否定式在动词原形前加don’t。 祈使句(Imperative Sentence) Turn off the TV, please. 请关上电视--请求 Go and wash your hands. 去洗手--命令 Let's play basketball. 我们去打篮球吧！--建议 Be kind to your classmates. 对同学要友好--叮嘱 Have a good day! 过个愉快的一天--祝愿 No smoking! 禁止吸烟--禁止 各种情感的祈使句 祈使句的类型 肯定：动词原形+宾语 +其它成分 否定：在句首加don’t。 Do型祈使句 Come in! Don't come in! 肯定： Be+表语 (名词或形容词) + 其它成分 否定： 句首加don’t。 Be quite in the library. Don’t be late for class. 肯定： Let +宾语+动词原形 +其它成分 否定： Don't let +宾语+动词原形 +其它成分 Let +宾语+not+动词原形 +其它成分 Don't let him go. Let's not go there. Let's go! 常用于第一人称和第三人称，表示建议和劝说等。 为表示礼貌，祈使句经常在句首或句末加please。 句末用please时，前面通常加逗号。 e.g. Go this way, please. 请这边走。 注意： “No+名词/动词 ing形式”表示禁止或规劝，常用于公共场所。 No photos! 禁止拍照！ No smoking！ 禁止吸烟！ 情态动词表示说话人的语气和情态，如请求、许可、意愿、可能等。 1.在形式上，情态动词一般没有人称和数的变化。 2.有的情态动词没有时态的变化，如must。 3.情态动词本身不能单独作谓语，必须和动词原形连用。 常见的情态动词有can、may、must、have to、should、would等。 1. 表示能力。 2. 表示许可。 3. 表示请求。 We can speak a little English. We can’t run in the hallways. Can you help me with my Chinese could也可表示请求，但比can的语气更委婉。 e.g. Could you tell him to call me back 1.must通常表示的是说话人的主观看法，语气比较强烈。 have to往往强调客观需要。 2.否定含义大不相同 mustn't表示“不准；禁止” don't have to表示“不必” 区别： Complete the sentences using can, have to / must, or can't / mustn't. 1.Don’t jump the queue. You _____ wait for your turn. 2.I _____ feed my dog many kinds of food, but I _____ give him chocolate. It is bad for him! 3. A: Can I leave the class if I don’t feel well B: Yes, but you _____ tell your teacher about it when you _____ be absent from class. 4. A: Hey! Can I look at your book 缺席；不在 B: Shh, we _____ talk quietly in the library. 5. A: Can you put on your seat belt We _____ wear one when we’re in a car. B: Sure. Thanks! must / have to can can't must / have to have to must / have to must / have to 插队 系好安全带 等待 Look at the first sign and read the rules. Then write rules for the other signs. In groups, brainstorm three rules for one of the places bel ... ...
