高中英语外研版选修8 Grammar 情态动词复习部优课件

1、Competition Edison always wondered why hens could hatch (孵) chickens while he was not able to.Question: Are the two modal verbs interchangeable (互换) ? If not, why?1. A big fire broke out in ABC hotel yesterday. Luckily, everyone _ run out of the building.2. She _ speak both English and French.can表示与

2、生俱来的能力或一种客观可能性，而be able to更加强调通过后天的学习和努力获得的能力，或者在某个客观的场合和背景下，能做到的事情。客观可能性Can/Could请求和允许 。can/maycant/Im afraid not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） can never/canttoo/enough/more表示“无论怎样也不过分”，“越越好” 你过马路的时候再小心也不为过。 You cant be too careful while crossing the road. Mary：Oh, Tom must have smoked here just

3、 now, I can smell it.Tina: Dear me! Didnt he see the sign on the wall? He mustnt smoke here!Mary: If he must, he can go out of the building.Tina: But in my opinion smoking is not a must for him. He could have avoided doing that. Im so tired! I have to do the training for at least 10 hours a day! Obl

4、igation (义务):Liu Xiang is so gifted in hurdle raceyet he must work hard to win the gold medal.So you must study hard. Although the chance of winning a medal is small, Ill try my best! Shi Dongpeng might win a medal at the Olympic Games.Certainty (可能性)May you succeed. 1.He _ be at home.A. may B. migh

5、t C.must2.He _ be at home, for he just called me from his home 15 seconds ago.A. may B. might C.mustThey_ be doing the experiment in the lab.Why？Because the lights are still burning.must1. 用于表示“意志”“决心” I will offer you any information you need.2. 表示“请求”Will you accept my invitation？3. 表示“总是，习惯于”He w

6、ill take a walk in the park every day.used towouldused to表示过去的事情， 现在不做would 过去的习惯动作，与现在无关 shall 用于第二、三人称肯定句，表示命令，警告，威胁，按规定 ; What shall we do this evening?用于第一、三人称疑问句，表示征求对方意见或请求You should keep your promise. 义务、建议It never occurred to me that she should lie to me again.“竟然”He should be 20 years old.表示推测“照说应该”Ability Ob