2017届高考英语牛津版一轮复习语法考点专练课件：9 情态动词和虚拟语气_高考复习指南

2017届高考英语牛津版一轮复习语法考点专练课件：9 情态动词和虚拟语气

　　can/could一般表示主语本身所具有的能力,意为:能,会;而be able to一般表示通过努力能做到某事。典例1 (2015浙江,4)It was so noisy that we hear ourselves speak. 答案　couldn't 解析　句意:这里如此嘈杂以至于我们无法听到自己说话。根据语境可知此处表达过去的能力故用couldn't。考点清单高频考点二　情态动词表推测情态动词表推测分为:对现在情况和过去情况的推测、对情况肯定的推测、否定的推测以及可能性的推测。对现在情况的肯定推测就用must,否定推测就用can't,可能性推测就用can/could,may/might。对过去情况的肯定推测就用 must have done,否定推测就用can't have done,可能性推测就用can/could/may/ might have done。做题时要判断是哪一种推测,还要判断出是对现在还是对过去情况的推测。典例2 (2015重庆,12)You be Carol.You haven't changed a bit after all these years. 答案　must 解析　句意:你一定是卡萝尔,这么多年过去了你一点也没变。根据语境可知此处表示对现在情况的肯定推测,所以要用must(一定)。高频考点三　情态动词表请求、许诺、允许 1.向对方提出或征求意见时一般要用比较委婉的语气,常用的句式有:Shall I/ he/they...?Could I...?May I...? 2.情态动词shall用于第二、三人称表示说话者命令、警告、许诺的语气。表示按照规章制度、法律、条例规定应该怎么做也要用shall。这是高考对shall 的考查热点。典例3 (2017北京,27) I have a word with you?It won't take long. 答案　Can/May 解析　句意:我能和你说句话吗?不会花很长时间的。本题考查情态动词的基本用法。can/may可以,表请求允许。高频考点四　情态动词表必要性 must语气最强烈,表示说话者坚决认为必须做某事;need语气要比must弱,表示说话者认为有必要做某事;should在表示该含义时,表示在义务上应该做某事。should还表示“竟然会,(将来)万一”。典例4 (2015北京,29)—Can't you stay a little longer? —It's getting late.I really go now.My daughter is home alone. 答案　must 解析句意:——难道你不能再多逗留一会儿吗?——时间不早了。我现在确实得走了。我的女儿独自一人在家。根据对话内容可知空格处表示“必要性”,故用must。情态动词+have done 意义 must have done 想必/准是/一定做了否定式为can't/couldn't have done could have done 本来能够做 can/could have done 过去可能会做 cannot/could not have done 1.过去不可能做 2.过去没能够做 may/might have done 也许/或许已经做了……,一般只用于肯定句或否定句中(在否定句中表示“可能不”),不用于疑问句。用might则表示语气更加不肯定高频考点五　情态动词+have done should/ought to have done 本该做而实际上未做 shouldn't/ought not to have done 本不该做而做了 needn't have done 本来不必做而做了 had better have done 要是当时做了就好了,用于事后的遗憾,含轻微的责备,其否定式had better not have done表达相反的含义 would rather have done 宁愿当时做了,其否定式would rather not have done表达相反的含义,两者都表示“后悔”之意 would like/love to have done 过去愿意做但未做成典例5 (2015天津,7)I have worried before I came to the new school,for my classmates here are very friendly to me. 答案　needn't 解析　句意:在进入这所新学校之前我本没必要担心,因为这里的同学对我很友好。根据语境可知此处表达“过去对某事担心过,但现在看来这种担心没有必要”,应该用needn't have done。高频考点六　虚拟语气