高一英语 Unit3  Celebration导学案

Lesson3  Grammar

Tips：All things in their being are good for something.(天生我材必有用)

Learning aim: learn the use of the modal verbs have to /not have to , can/can’t, ought to /ought not to

Learning methods: observe----learn-----summarize------use

Learning steps:

StepI: Underline all the following words in the texts and translate them.

have to , don’t have to, ought to, ought not to, can’t,can

StepII: Match the verbs to their meanings.(A级)

1 have to              a) not necessary

2 don’t have to         b) necessary

3 can                 c) not allowed/not possible

4 can’t                d) allowed/ possible

5 ought to             e) not advisable

6 ought not to          f) advisable

StepIII:Transtrate the following sentences.(B级)

1.1)I can’t go out now, I have to look after my baby .

______________________________________

2)I must find a job,my parents can’t support me any longer.

_____________________________________________

3)— Must we hand in our exercise books today?

— Yes, you must. (No, you don’t have to/need’t.)

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总结：must 和have to表示___________，但must表示___________观，have to表示_________观(如例句1，2所示)

读一读，记一记:

must与have to有下列几点不同：

① must表示的是说话人的主观看法，而have to则往往强调客观需要。

The play is not interesting. I really must go now.

I had to work when I was your age.

② must与have to 的时态差别： have有时态的变化,如三单has, 过去时had ,表示 客观上的不得不，能与所有 时态一起。must为情态动词, 无时态的变化 , 表示主观上的必须, 需要。