Unit 1 Food for Thought Grammar Modals课件-2023-2024学年高一外研版（2019）英语必修第二册

Lead-in I was able to hold a knife and fork—and chopsticks! But there are still some dishes that Dad dare not try even after many years of marriage to my mother. Mum and I just have to find a way to get him into the kitchen. We had better not eat too much roast food as it may make us suffer from heat inside our bodies. “You needn’t try it if you don’t want to,” Mum said. a. be able to b. dare not c. have to d. had better e. needn’t 1. be afraid害怕 to do something 2. not be necessary to do something 3. give advice to do or not to do something 4. be necessary必要的 or give strong advice to do something 5. have the ability能力 to do something Match the meanings to the phrases. Modals 2 Grammar：Modals UNIT 1 Food for Thought 3 情态动词(Modals)表示说话人的某种语气或者情绪，如：可能，意愿，猜测，义务，需要等。情态动词本身具有一定的词义。常见的情态动词包括can (could), may (might), will (would), shall (should), ought to,had better, must, have to，need, dare, used to等。 本单元主要讲情态动词：be able to, dare, have to, had better, need. 1. 基本特征： (1)情态动词不能单独做谓语，后面接动词原形； (2)情态动词没有人称和数的变化（be able to，have to除外） 2. 基本用法： be able to dare＆need have to had better be able to do sth. = have the ability to do sth. 1.be able to 后接动词原形，表示某人能够做某事，有时态和数的变化。 2.be able to 用于过去时态时，表示 “某人过去或当时成功地做了某事”=managed to do sth/succeeded in doing。 If I work harder, I will be able to make greater progress. There was a big fire yesterday. Luckily, everyone was able to escape from the fire . dare not do sth.不敢做某事 = be afraid to do sth. 1.dare 作情态动词时， 没有时态和数的变化，否定式是dare not，主要用于否定句和疑问句中。 2.dare 用作实义动词时，后接to do，有时态和数的变化。用在肯定句中。 She dare not go out alone at night. She dares to go out alone at night. needn’t do sth.不必做某事 = not be necessary to do something 1.need 作情态动词时，没有时态和数的变化，用于否定句needn’t或疑问句中。 2.need 作实义动词，有时态和数的变化；后接to do，常用于肯定句 You needn’t come so early. He needs to earn more money to support such a large family. 1.have to 有时态和数的变化，强调客观需要，意为 “不得不”否定形式是don’t have to，相当于needn’t不必。 2.must无时态和数的变化，强调主观意愿，意为 “必须”。 have to 不得不= be necessary or give strong a