高一英语 Unit3 Celebration导学案
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.)
________________________________________________
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。
③ 二者的否定意义不大相同。如：
you mustn't go. 你可不要去。
you don't have to go. 你不必去。
④ 询问对方的意愿时应用must。如：
must i clean all the room?
2 1)can you speak english?
__________________________________________________ can表示能力（如体力和脑力方面），意为“__________”等can表示能力时，还可用be able to代替。如：
i'll not be able to come this afternoon.
2)表示请求或允许，多用在口语中，意为“__________”等。
— can/could i go now?
— yes, you can.（回答语中不能用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）
