助动词情态动词

,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,单击此处编辑母版标题样式,单击此处编辑母版文本样式,第二级,第三级,第四级,第五级,*,简明实用英语语法教程,第五章 助动词和情态动词,1,助动词和情态动词,用,法决定词性,助动词和情态动词,均为辅助动词表达意义的动词。,1.,助动词,用于表示人称、时态和语态,1),be, have, do,2),shall/should, will/would (,兼做情态动词）,2.,情态动词,用于表明作者要赋予动词的情态意义。,1),must, may/might,2) shall/should, would, ought,3) need, dare, have, used, be able, had better/had best,情态动词,准,确把握句子的语气,是正确使用情态动词的要点和难点。无论是揣摩别人的语气，还是表达自己的语气，都需要清晰分辨语境中情态动词的含义。,有些词兼有助动词和情态动词的功能前者用于表示人称、时态和语态，后者用于表明作者要赋予动词的语气。要注意从句子结构和语义两个方面加以区分。,2,助动词,时态和语态的承载者,1,1,.,be,1) 构成进行时态：,be + v-ing,A.,当,be,为,am/is/are,时，与不同的人称和数的主语配合，构成现在,进行时。,B.,当,be,为,was/were,时，与不同的人称和数的主语配合，构成过去,进行时。,2) 构成完成进行时态：,have + been + v-ing,A.,当,have,为,have/has,时，与不同的人称和数的主语配合，构成现在,完成进行时。,B.,当,have,为,had,时，与不同的人称和数的主语配合，构成过去完成,进行时。,3) 构成被动语态,be + p.p.,3,助动词,时态和语态的承载者,2,2.,have,1,) 构成完成时态：,have + done,A.,当,have,为,have/has,时，与不同的人称和数的主语配合，构成现,在完成时。,B.,当,have,为,had,时，与不同的人称和数的主语配合，构成过去完成,时。,2) 构成完成进行时态：,have + been + v-ing,3),构成不定式等非谓语动词的完成式：,have+p.p./ having+p.p.,等。,3.,do,1) 构成疑问/否定。,2),用于强调动词：,I did do it yesterday.,3),用于代替上文中刚提及的动作，以避免重复：,He lives here but I,do,n,t.,4,助动词,时态和语态的承载者,3,4.,will,1）,表示将来，用于各个人称。,2）表示请求，用于第二人称的疑问形式：,Will you have an apple?,5.,would,1),表示过去将来，用于各个人称。,2）表示婉转请求，用于第二人称的疑问形式：,Would,you help me?,3,）表示婉转看法,，,用于第一、三称：,He would mind your going. I,d go there with you.,4),表示过去习惯性动作或倾向：,When he was young, he would often walk here.,5),用于虚拟语气,A.,条件句：,I should be obliged if you wouldn,t George me.,B.,结果句：,If we were men, we would be doing something now.,5,助动词,时态和语态的承载者,4,6.,shall,表示将来，用于第一人称。,7.,should,1),表示过去将来，用于第一人称。,2）表示婉转请求，用于第一人称：,I should like to phone my lawyer.,3),用于某些句型的谓语中。,A.,宾语从句：,He suggested that we should do it at once.,B.,主语从句：,It is better that he should hear from you.,4),用于虚拟语气。,A.,条件句：,If you should be passing, do come and see us.,B.,结果句,用于第一人称:,I should have helped her if she had asked me.,6,情态动词,-,准,确把握句子的语气,明晰具体功能,1,1.,may,1),可否,A.,用于问句:,May,I use your phone?,B.,用于陈述句:,You,may,come if you wish.,2),推断,A.,现在,可能:,He,may know,the answer.,B.,过去,可能:,He,may have gone,aboard.,3),用于状语从句，表示目的、让步等:,Speak clearly so that they,may,understand you.,Try as he,may, he will not pass the exam.,4),祝愿：,May,you be happy!,7,情态动词,-,明晰每一个情态动词的具体功能,2,2.,might,1),可否, 含义比,may,委婉。,A.,用于问句：,Might,I use your phone?,B.,用于陈述句：,You,might,call at the chemist on the way home.,2）,may,的过去式, 用于间接引语:,A.,表示,“,可以,”,：,I,thought,you,might,stay here.,B.,表示,“,可能,”,：,He,said,he,might,be late.,C.,用于状语从句，表示目的、让步等:,I lent him $500 in order he,might,go for a holiday.,Try as he,might, he could not pass the exam.,3),推断, 与,may,用法相同。,A.,现在,可能:,He,might,know the answer.,B.,过去,可能:,He,might have gone,aboard.,8,情态动词,-,明晰每一个情态动词的具体功能,3,4) 轻微批评、抱怨。,A.,针对现在：,You,might tell,me if you,re going to be late.,B.,针对过去：,You,might,at least,have phoned,me if you,re not,coming.,3.,must,1),必须、一定。,A.,指现在或将来：,You,must,give up smoking. I,must,remember to post the,letter.,B.,指过去用,have,的过去式,had(,比用,must,含义清楚):,I had to go to see the doctor.,2),否定式,must not/mustn,t,表示,“,禁止、一定不,”,：,Cars,must not,park in front of the entrance. We,mustn,t,be,late.,9,情态动词,-,明晰每一个情态动词的具体功能,4,3),推断。,A.,现在,可能:,He,must,know the answer.,B.,过去,可能:,We,must have read,the same report.,4) 责任、义务,，,与,should/ought,含义类似：,You,must,see the film; it,s wonderful.,4.,should,/,ought,1) 责任、义务,A.,指现在或将来：,The police,should,do something about it.,The machine,ought,to be cleaned once a week.,B.,指过去:,You,should,have checked the time before you left.,You,ought,to have told me about it earlier.,10,情态动词,-,明晰每一个情态动词的具体功能,5,2),ought,还用于表示揣测,。,He,ought,to pass the exam. The water ought to have boiled,now.,We,ought,to be hearing from Jane soon.,5.,shall,1),疑问形式征求意见，用于第一人称:,What time shall I come?,Let,s do it again, shall we?,2),表示规定、许诺、命令、警告、决心等，用于各个人称：,I shall write to you at the end of the month.,If you want a computer, you shall have one.,A player shall be sent off for using bad language.,need,11,情态动词,-,明晰每一个情态动词的具体功能,6,6.,need,1),表示,“,不必,”,，,A.,用于否定句,: You,needn,t,come to the meeting.,B.,用于含有半否定词的句子：,C.,用于宾语从句时，主句为过去时，依然用,need:,He says/said I,needn,t,pay till the 30,th,.,2),用于疑问句:,Need,we come tomorrow?,7.,dare,1),表示,“,敢,”,，,A.,用于否定句。,I,daren,t,ask her to do that.,B.,用于含有半否定词的句子：,I hardly dare to think of it.,12,情态动词,-,明晰每一个情态动词的具体功能,7,2),用于疑问句和条件句：,Dare,you interrupt him? I wonder if she,dared,come home.,3),用于,I dare say, don,t you dare,结构：,I,dare say,you,re right.,Don,t you dare,touch that vase.,8,have,表示客观上的必要性，后接带,to,的不定式.,1),肯定式：,We,have,to be careful in such matters.,2),否定式和疑问式：,You don,t,have,to get up early. Do you,have,to leave so soon?,3) 可用于各种时态:,We,ll have,to help him as much as we can.,4,) 可用于各种语态:,A lot of letters,had,to be answered.,5,) 可用于复合谓语,: We,may have,to cancel the plan.,13,情态动词,-,明晰每一个情态动词的具体功能,8,9.,had better/ best,d better,1),后接不定式的一般式或进行式（均不带,to)。,A.,接不定式的一般式:,We,d better,go,before it gets dark.,What,had we better,do?,2),接不定式的进行式:,I think we,d better be going,.,3) had best,与,had better,相似：,I,had best,be going now.,14,试题与思路,（助动词和情态动词）,1,1. -,Is John coming by train?,- He should, but he _ not. He likes driving his car.,A. must B. can C. need D. may,选,D。,从上下文,coming by train,和,driving his car,可知有两种可能性，则关于,driving his car,的推测属于,not sure,一类, 因此选,D。,2. It has been announced that candidates _ remain in their seats,until all the papers have been collected.,A. can B. will C. may D. shall,选,D。,根据上下文可知空格处应有一个表示意图、警告等含义的词语，,shall,就是这样一个词语，它可用于各种人称。,15,试题与思路,（助动词和情态动词）,3,5.,He _ here by now, for he took the early bus.,A. ought to have arrived B. must arrive,C. may have arrived D. can arrive,选,C。,从,took the early bus,可知，,arrive,的动作应发生于过去，即句子英表示对过去情况的推断，所以应该用含有完成式的不定式的选项。,ought,表示,“,责任、义务,”,，不用于表示对过去的推测，只有,may have arrived,合理。,6.,I wonder how he _ that to the teacher.,A. dare to say B. dare say C. not dare say D. dared say,选,D。,此句从句中的动作应发生于过去，故,dare,应该用过去式,dared。,若发生于现在，则应该用,dare say(,情态动词用法）或,dares to say（,行为动词用法，现在时) 。又，,dare,的情态动词用法否定式应为,dare not do sth。,16,试题与思路,（助动词和情态动词）,4,7. -,I saw Ann in the library yesterday.,-,You _ her; she is still abroad.,A. must not see B. can,t have seen C. mustn,t have seen D. couldn,t see,选,B。,由,“,yesterday,”,可知应是对过去情况的推断，因此应该用,“,情态动词+完成式的不定式,”,的结构来表示；又因,“,mustn,t,”,表示,“,禁止,”,而不可用。,8.,I _ them, but I wasn,t able to.,A. ought to have helped B. must have helped,C. might help D. needn,t have helped,选,A。,应该用,“,情态动词+完成式的不定式,”,的结构来表示对过去情况的推断。,从,“,wasn,t able to,”,可知言者原要,“,help them,”,但限于能力而未实现；从表达,“,责任、义务,”,需要，应该用,should/ought,这样的情态动词,。,17,