Unit 1 Grammar（情态动词）-高中英语人教版必修三课件 (共17张PPT)

1.Ability (能力): I am confident that we can defeat the epidemic! can/could: 1. can 表示能力或者一种客观可能性,还可以表示请求和允许 。 Learning English _____ be difficult. can _______ I use your computer? Can can/could: 2.在疑问句中，用could可表示请求，语气较委婉。 — ____I have the television on? — Yes, you _____. / No, you _____ Could He asks if he ____ smoke here. could can can’t/I’m afraid not can/could: 3.表示惊异、怀疑、不相信的态度。（主要用在否定句、疑问句或惊叹句中） He’s such a nice person that he ______ commit the crime! can’t 你怎么会如此地粗心！ How can you be so careless! __________ this be true? Can can/could: 4. can never/can’t……too表示“无论怎样…也不过分”，“越…越好” 。 你过马路的时候再小心也不为过。 You can’t be too careful while crossing the street. 注意： must可表示“坚持，一定要”（常用于固定句型：if you must do sth. 如果你非得要做某事） 如果你真的要走，那就悄悄离开。 If you leave, do it quietly. must You must wear a mask when you go out, or you will be easily infected. must 2.Certainty (可能性) : Since the epidemic is not over, we may not start school until April. 1.He _____ be at home.(多选) 2.He _____ be at home