【同步导学】人教版高中英语必修三导学案：Unit 2 Healthy Eating Grammar.doc

m3 unit 1 festivals around the worldsection vi grammar modal verbs学习目标：掌握情态动词的基本含义和用法。学习过程语法知识预习探究一 我的观察下文是学校的一些规定，你能搞清楚，哪些事可以做，哪些事不能做吗？ students mustnt leave the campus at school hours, so we have to have lunch at school. however, we dont have to bring your lunch-boxes because we have a dining hall inside the school. we ought to be tidy and orderly there, but luckily for us, we neednt wash up after dinner. 二 我的发现:请你写出我们本单元要学习的情态动词的汉语意思。 ought to ought not to have to dont have to mustnt neednt 三 我的讲解1. must和mustnt 1）must表示“必须”，是一种语气很强的要求。否定式must not(mustnt)表示 “不准”,“禁止”等。在回答带有must的问句时，否定式常用need not(neednt)或dont have to 表示“不必”，而不用must not (mustnt)。must i be home before eight oclock? yes, you must./no, you neednt./no, you dont have to.2）must表推测，一般只用于肯定句中，表示“一定”，“必定”。you must be very tired after such a long walk. 表示对过去事情的推测，用must+完成时。you must have left your umbrella in the theatre. 当must表推测之意时，其否定形式常用can not而不用must not。his car is still here. he cant have left 如果表示对正在发生的动作的推测，就用must+进行时。dad is always an early bird. he must be taking his usual morning exercise in the park now. 3）must表必然性 you must catch cold if you dont put on more clothes.。4) must 表示“一定要（语气很强的邀请）” 和“非得（嫌弃对方固执）”you must stay for dinner. must you play the piano at such a late hour?2. have to 和 dont have to/neednt 1) have to表示“必须”，“不得不”，在这个意义上与must很接近，但must表示的是说话人的主观看法，而have to 表示的却是客观需要。you have to work hard to make a living. you must do what i tell you. 2）have to 有更多的时态形式：现在时，过去时，将来时等，而must只有现在时形式。we had to be there at 8:00. i shall have to go to school tomorrow.。3）dont have to 表示“不必”，“不一定要”, 意思是说某事可以做也可以不做，在这个意思上neednt 则表示根本没必要做。you dont have to win all the matches to be a top club. we will do a thorough cleaning to the house but we neednt clean the roof. 3. ought to/ ought not to 1）ought没有人称或时态的变化，后跟带to的不定式。常译作“应该”，“应当”等，和should同义，只是口气稍重一些。其否定式为ought not to (oughtnt to )，疑问式为ought i /you to?such things ought not to be done. 2）表可能性,意思是“按常理会应该 ”mary ought to be home by now.3）表示没有履行过去的义务时，用“ought to +完成时。you ought to have told me about this earlier. (but you didnt)四 我的练习一、情态动词填空1. jack described his father, who a brave boy many years ago, as a strong-willed man.2. mark have hurried. after driving at top speed, he arrived half an hour early.3. you _ park here! its an emergency exit.4. you buy a gift, but you can if you want to.5. we _ respect the old and take care of the young; this is traditional chinese virtue. 6. all the deal lines _ be closely followed, or the whole project will be delayed. 7. the boss _ ignore the health of the workers. we have got to talk to him about t