高一英語(yǔ)Festivals around the world教案
過(guò)去時(shí) dared he do? 現(xiàn)在時(shí) do you/does he dear (to) do?
過(guò)去時(shí) did he dare (to) do
3. can 和 may
考試中主要測(cè)試can，may或could，might表示可能性的區(qū)別及對(duì)may構(gòu)成的疑問(wèn)句的回答。
（1）can, could, may, might都可以表示可能性.can, could表示潛在的可能性或理論上或邏輯判斷上存在的可能性；而may, might則表示事實(shí)上的可能性。此外，can還具有“有能力”的意思，而may與might則不具此意。例如：
according to the weather forecast, it may rain tomorrow.
any man with a little sense can see that he is wrong.
（2）may i / we …？這一類疑問(wèn)句的肯定回答為yes, please.或certainly；否定回答為please don’t.或no, you mustn’t. 例如：
“may we leave now?” “no, you mustn’t. you haven’t finished your home work yet.”
4. can 和 be able to
can 與 be able to 都可以表示能力，但兩者在用法上有點(diǎn)差異：can (could)表示主觀能力，不表示意愿，它的將來(lái)時(shí)用will be able to; be able to表示主觀意愿，強(qiáng)調(diào)要克服困難去做某事。例如：
1）my grandma is over seventy, but she can still read without glasses.
2）he is able to give up his bad habits.
5. must 和 have to
must 和 have to 都可以表示“必須”，但有幾點(diǎn)區(qū)別：
（1）must 強(qiáng)調(diào)“內(nèi)在的職責(zé)”、“義務(wù)”，而have to 強(qiáng)調(diào)“外界壓力”、“不得已而為之”。
（2）have to可用于多種時(shí)態(tài)，而must一般用于現(xiàn)在時(shí)，其過(guò)去時(shí)與將來(lái)時(shí)分別由had to與shall / will have to代替。
（3）在回答must引起的問(wèn)題時(shí)，如果是否定的答復(fù)，不能用mustn’t，而要用needn’t或don’t have to，因?yàn)閙ustn’t是“一定不要”、“一定不能”的意思。例如：
1）you must come to the classroom before eight.
2）it is raining hard outside, but i have to leave now.
3）“must we do it now?” “no, you needn’t.”
6. used to +do, be used to +doing和be used to +do
（1）used to +v意為“過(guò)去常常”，“過(guò)去一直”；be used to +v-ing / n（名詞）意為“習(xí)慣于”；be used to +v意為“被用來(lái)（做某事）”。
（2）used to只表示過(guò)去，而be used to +v-ing / n可表示現(xiàn)在、過(guò)去或?qū)?lái)。例如：
1）he used to smoke. now he doesn’t.
2）he’s quite used to hard work / working hard.
3）the knife is used to cut bread.
7.用作情態(tài)動(dòng)詞的其他短語(yǔ)
would rather, would sooner, would (just) as soon, had rather, had better, had sooner, can not but, may (just) as well等可用作情態(tài)動(dòng)詞。例如：