人教版（新课程标准）必修三 Unit 2 Healthy eating 情态动词教学设计

人教版高中英语必修三 Unit 2 Healthy eating
Grammar情态动词（Modal verbs）
一、教学设计
【教学目的】
Students will know the usage of the modal verbs.
Students will learn to use the modal verbs.
【教学流程】
Step 1 ought to 与ought not to的用法
1. ought to多表示责任、义务，语气强烈，与should意义相近，但should常表示劝告、建议、 命令。否定形式为ought not to。
eg. By now his restaurant ought to be full of people.
You ought not to go.
2. should和ought to的不同：
1) should, ought to表示“应该”，ought to表示义务或责任，比should语气重。
eg. I should help her because she is in trouble.
You ought to take care of the baby.
2) 表示劝告、建议和命令。should, ought to可通用，但在疑问句中常用should。
eg. You should / ought to go to class right away.
Should I open the window
Step 2 have to 和don’t have to的用法
1. must, have to比较：
1) 表示必须、必要。
eg. You must come in time.
在回答引出的问句时，如果是否定的，不能用mustn’t（禁止，不准），而用needn’t, don’t have to（不必）.
eg. — Must we hand in our exercise books today
— Yes, you must.
— No, you don’t have to / you needn’t.
2) must是说话人的主观看法， 而have to则强调客观需要。Must只有一般现在时， have to 有更多的时态形式。
eg. The play isn’t interesting. I really must go now.
I had to work when I was your age.
2. must表示推测、可能性（只用于肯定的陈述句）
eg. You’re Tom’s good friend, so you must know what he likes best.
Your mother must be waiting for you now.
Step 3 mustn’t的用法
虽然must是表示“必须”的意思,但是用于否定式时,mustn’t却表示“不要、不能、禁止”的意思,而不是表示“不必”.这是中考的一个考点.
eg. You mustn’t leave here.你不能离开这儿.
You mustn’t go swimming today.今天禁止你去游泳.
You mustn’t drive so fast.你不能开这么快.
Step 4 needn’t的用法
needn’t 不需要;不必;强调客观条件。常做must问句的回答：
eg. Must I finish my homework today No, you needn't
You needn't be oversensitive. It has nothing to do with me.
你不必多心，这事与我无关。
You needn't truckle to your aunt like that. you are a grown woman now.
你没有必要那样胆小顺从你的伯母，你现在是一个成年妇女了。
Children below 120 cm needn’t pay fare.
120公分以下的小孩不必买票。
Practice：
Read these dialogues and complete them with the proper modal verbs.
JOHN: We should get to the theater by seven o’clock. What time do you think we should leave
SARAH: I think we have to leave home at six o’clock, or we won’t arrive there in time.
GEORGE: I don’t feel well. The doctor told me that I have to give up smoking. He also gave me the medicine. Do you think it’ll do me any good
AMY: If you follow the doctor’s advice, it will help you.
SALESMAN: This car is one of the safest on the market. Even so, you mustn’t be silly and drive without wearing a seat belt.
CUSTOMER: I will never do that!
RON: Let’s go to Carla’s party tonight!
TOM: Well, I don’t mind going as long as I don’t have to dress up.
RON: That’s OK. You don’t even need to wear a tie if you don’t want to.
SUSAN: Do you know where Alan is I can’t find him anywhere.
ROBIN: Well, he couldn’t have gone far. His bag is still here.
Step 5 Summary
The structure of the lesson is as follows:
Step 6 Homework
情态动词(Modal verbs
)
ought to/ought not to
have to/don’t have to
mustn’t
needn’t