1、第三课时 Grammar Focus4c单元语法清情态动词must，can/could，may/might表示推测时，要根据肯定、否定或疑问的不同形式选用不同的情态动词。“情态动词do sth.”表示对现在事情的推测；They must be in the classroom now.他们现在一定在教室里。“情态动词be doing sth.”表示对正在发生的事情的推测；Its eight oclock.My grandfather must be doing sports in the park.现在是八点，我的爷爷一定正在公园锻炼。“情态动词have done sth.”表示对过去或已完成
2、事情的推测。Peter may/might have been hurt in the car accident.彼得可能在车祸中受了伤。肯定推测(1)must用于肯定句，意为“准是；一定”，后面接动词原形，表示较有把握的推测。Ive had no sleep for 48 hours.我已经48小时没睡觉了。You must be exhausted.你一定筋疲力尽了。【注意】mustnt表示“禁止；绝不允许”。(2)may，could，might意为“可能；也许”，表示可能性较小的肯定推测。You may be right.你可能是对的。He could/might be running
3、for exercise.他可能正在跑步锻炼。(3)can用在肯定句中，表示理论上的可能性。Smoking can cause cancer.吸烟有可能引发癌症。否定推测(1)表否定推测时，cant/couldnt语气最强，指“不可能”，带有惊异、怀疑的感情色彩。The story sounds reasonable，but it cant be true.这个故事听起来合情合理，但不可能是真的。(2)may not/might not/could not表示不太有把握的否定推测，意为“可能不(会)是”。He could not/might not be at home.Im not sure
4、.他可能不在家，我不确定。疑问句中的推测疑问句中的推测，常用can或could，意为“可能”。There is someone outside.Who can it be？外面有人，会是谁呢？句型：(1)“Whose一般疑问句？”(2)“Whose名词一般疑问句？”答语：(1)使用名词所有格或物主代词来回答。(2)使用“belong to sb.”结构来回答。Whose is this umbrella？/Whose umbrella is this？这把雨伞是谁的？Its Marys./It belongs to Mary.它是玛丽的。【语法精练】一、单项选择。1.(2021辽宁铁岭、葫芦岛
5、)Sit down，please.You _ be tired after standingfor so long.AcouldBcanCmustDmight2.The girl in the music room _ be Celia.She has gone to the dining hall.AcantBmustCmayDmight3.(2021辽宁朝阳)What will the weather be like tomorrow?It _ be rainy，cloudy or sunny.I am not sure.AmustBmayCcantDshouldCAB4.(2021云南中
6、考)You _ take photos here!Look at the sign.It says“Nophotos”Sorry，I wont.AmustBneedCmustntDneednt5.(四川攀枝花)Excuse me，is this the right way to the library?Sorry.I am not sure.But it _ be.AneedBwillCmustDmightCD二、根据汉语意思完成下列句子。6你从今天早上开始就没有吃过东西。你一定饿了。You havent eaten anything since this morning.You _ _ hu
7、ngry.7他明天可能来，但是我不太确定。He _ _ tomorrow，but I am _ _8我的书不见了。会是谁拿走了它呢？My book has disappeared.Who _ _ _ it?must bemight/may come not surecould/may/might have taken9这不可能是我们的英语老师，他去美国了。It _ _ our English teacher.He has gone to America.10这是谁的黄色发带？一定是莉萨的，她喜欢黄色且留有长发。Whose yellow hair band is this?It _ _ _She
8、 likes yellow and has long haircant bemust be Lisas三、从括号内选择适当的单词完成短文。Sally looked out of her window at the grey sky.She wondered if it was as cold as itappeared.Or it 11._(might/should)be even colder.Right away she decided sheneeded her cotton slippers(拖鞋)to keep her feet warm.However，the trouble wa
9、sthat she hadnt seen them for a week!“Where 12._(could/must)they be？”she thought.“Oh，yes.They 13._(may/can)be under my bed.Usually I put them there，”Sally said to herself.But they werent there.mightcouldmay“Mom，I 14._(cant/mustnt)find my cotton slippers under my bed.Wheredo you think they 15._(could
10、/should)be？”Sally asked her mother.“Go and ask your sister Maria or your brother Henry.They 16._(might/will)know where your slippers are，”answered Sallys mother.Sally asked Maria whether she knew where her cotton slippers were.“I dont know where they are.But our brother Henry 17._(may/can)knowit，”an
11、swered Maria.“On Tuesday evening，I saw your slippers next to our dog Cocos bed.Im surenow they 18._(must/will)be there，”said Henry.Sally found her slippers under the dogs bed at last.cantcouldmightmaymust【课时精练】四、根据句意及汉语提示填写单词。19My father often runs _(在户外)to keep healthy.20_(无论何时)I felt down，he would cheer me up.21You may catch a cold without wearing a(n)_(外套).22The great scientist spends most of his time in his _(实验室).23(四川乐山)She was so _(瞌睡的)that she went to bed early last night.outdoorsWhenevercoatlaboratory sleepy