Unit 5 The value of money Discovering Useful Structures 课件-2022-2023学年高中英语人教版（2019）必修第三册

必修第三册 Unit 5 The Value of Money Discovering Useful Structures B. CONTENTS: 1. The characteristics of modal verbs 2. List of modal verbs 3. Usage of modal verbs 4. Example of modal verbs B. 1. The characteristics of modal verbs Modals are special verbs that behave irregularly in English. ①They are different from normal verbs like "work, play, visit..." ②They give additional information about the function of the main verb that follows it. They have a great variety of communicative functions. B. 1. The characteristics of modal verbs A. They never change their form. You can't add "s", "ed", "ing"... 没有人称、数及时态的变化 They are always followed by an infinitive without "to" (e.i. the bare infinitive.) 后加动词原形 They are used to indicate modality and allow speakers to express adding meanings. 表达情感和态度 B. 2. List of modal verbs （9） M M M W W C C S S ust ay ight ill ould an ould hall hould dare/need not/ought to/have to/ you’d better B. 3. Usage of modal verbs Modal verbs are used to express functions such as: 许可 能力 义务；责任 禁令 不必要 建议 可能性 概率 Permission Ability Obligation Prohibition Lack of necessity Advice possibility probability B. Page 54 Functions & Meanings Example Necessity Possibility Obligation Request Advice Intention We can discuss it now. You must do it at once. Would you please pass me the salt? You needn’t have stayed. You ought to help him. I would rather do it myself. 义务，职责 必要，需要 may/might, could Mustn’t could have to Should; had better do Will do; be going to do B. 4. Example of modal verbs B. B. B. 5. Attention!!!情态动词 + have done may/might have done 可能做过某事 must have done 一定做过某事 could have done 可能做过某事；本可以做某事（实际上没有做某事） needn’t have done 本不需要做某事（实际上做了某事） ought to have done = should have done 本应做某事（实际上没有做某事） Would表示过去反复、习惯发生的动作或某种倾向 B. Read the passage and fill in the blanks with suitable modal verbs in the box. may must can ought to might had better would should In the film The Million Pound Bank Note