八年级英语上册Unit9Canyoucometomyparty语法讲解素材.docx

Unit 9 Canyou come to my party?单元语法聚焦九情态动词can, have to的用法【正面阐述】1can的用法can是一个情态动词，其后接动词原形，其否定形式是_，它的过去式为_ ，否定形式为_。can的用法如下：can的用法意思例句表示请求、许可“能不能，可不可以”，相当于may，但没有may正式。Can you go with me?你能和我一起去吗？表示能力能，会He can swim，but I cant.他会游泳，但我不会。表示推测“可能”，常用于否定句和疑问句中。Mr Wang cant be at school now.王老师现在不可能在学校。表示禁止不准；禁止You cant smoke inthe hall.大厅内禁止吸烟。注意：can表示请求或用于发出邀请时，如果接受对方的邀请时常用“Sure，Id love (like) to. /Certain- ly. /Of course.”等回答；如不接受，常用sorry等有礼貌地拒绝，但一般情况下需要说明不能接受邀请的原因并表示歉意。如：Can you come to my birthday party tomor- row?明天你能来参加我的生日聚会吗？Sorry, I cant. Im going to visit my grandpa.对不起，我不能去。我打算去看望我爷爷。2have to的用法have to的用法例句意为“不得不，必须”，它强调一种客观情况，有单复数及时态的变化，其第三人称单数为_，过去式为_。His mother is ill. Hehas to stay at homeand look after her.他妈妈病了。他不得不待在家里照顾她。由have to构成的句子的否定句、疑问句需用助动词_的适当形式来完成。Do you often have to goto work at eight?你常常得在八点钟上班吗？3have to与must的区别(1) have to意为“不得不，必须”，它强调一种客观情况。must意为“必须”，着重于说话人主观上认为“有义务，有必要”。如：We have to pay a fine.我们不得不交罚款。You must do it yourself你必须自己做。(2)have to有单复数及时态的变化，must无人称、时态、数的变化。如：She has to finish her homework.她必须完成作业。She must finish her homework.她必须完成作业。(3)过去时及将来时的句子常用have to，而不用must。They had to send him to his home.他们不得不送他回家。She had to do some washing yesterday.昨天她不得不洗衣服。答案1cant could couldnt2has to had to do【反面解读】1人称和数的误用误：He cans swim.正：He can swim.2时态的误用误：He can play the piano when he was eight years old.正：He could play the piano when he was eight years old.3情态动词的误用误：We have to obey the traffic rules.正：We must obey the traffic rules.【实战演练】()1.Can you stay here for lunch?Sorry,_ .I have to see my par- ents.A.I cant B.I shouldntC.I mustnt D.I dont()2. I cant stop playing computer games.For your health, my boy, Im afraid you_A. can B. must C. have to D. may()3. Could you please close the door?Yes, I_.A.can B.must C.could D.should()4. Can you play the piano?Yes, I_. I often practice it on weekends.A neednt B. need C. cant D. can( )5.Whos the man over there? Is it MrBlack?-It_ be him. Hes much taller.A cant B. mustnt C. should D. may( )6. Mr Wang, must I come again on Sun-day morning to c