Unit7 情态动词-郑天生中学英语语法

Unit7情态动词 词 7-1情态动词概述 情态动词也是一种助动词,表示说话人的语气或情态,也叫情态助动 词。情态动词有:can,may,must, ought to, have to,need,dare,shal,wil should和woud。情态动词的变化很有限,有形式变化的词只有几个 现在式 can have to dare 过去式coud might would had to ①情态动词表示的时态有限,要表示某种时态,有时需要换词。比如:can表示将来 时,可用: will be able to。 注]情态动词本身是助动词其前面一般不再加助动词。如不能说: will must de(但 will have to例外,因为 have to是半助动词 8can与 could, may与mght有时不是时态的区别,而是语气或客气与否等的差别。 若表示过去时,可用: can have done, may have done等短语 通常情况下,情态动词的否定式,直接在情态动词的后面加ηot,如: an not cannot e cant), may not, should not (shouldnt), will not won't), need not( needn't)等。构成疑问句时则直接将情态动词提至句 首。 had better的否定式为 had better not,加原形动词。但 ought to,have to和 used to这三个保留不定式符号的情态动词的否定式和疑问句的构 成略有不同。 7-2may, might的用法 1 may ①表示“允许”或“请求”,即表示说话人同意、许可或在疑问句中征询对 方的许可。其否定式可用 may not.在表示“不可以”“不许”“禁止”阻止”等 意思时,常用 must not( mustn't)代替 may not。如: You may go now.你现在可以走了。 May| borrow your raincoat?我可以借用你的雨衣吗? Yes, you may.是的,可以。 No, you mustnt.不,不可以。 81 口郑天生中学英语语法 Middle School English Grammar 口郑天生中学英语语法 Middle school English Grammar I borrow your MP3? (中考2005年山西) 题 -Sure. Here you are B. Should C. Must Would 【答案选A本题考查情态动词。向别人借东西,应有礼貌,may的语气较委婉、客气 ②表示说话人的猜测:认为某一事情“或许”“可能”(现在和将来)发生。其 否定式用 may not( mayst),表示“可能不”。如: Linda may come today.琳达今天可能来。 Dr. Li may not be there at this moment..李医生此刻可能不在那儿 She may not go to the concert tonight.今晚她可能不去音乐会了。 -Who's that woman with ann? [题] -'m not sure. It be her mother (中考204年襄樊) A. may B. can C. will D. must 【答案选A】由前句 m not sure.可知,表可能性此处用。如: ③用在may.but.”结构,表示“我承认,尽管,但是…… It may be a very fast and comfortable car, but it uses a lot of gas 它是一辆很快而又舒适的汽车,但是它很耗油。 I might wait and wait, but there was no sign of him 尽管我等了又等,但是不见他的人影。 ④用于 although/ though, Whatever, Whenever, however, wherever 等引起的让步状语从句。如 However hard the boy may try, he cant do it wel 这男孩不管怎么努力,总是做不好 Wherever you may hide( Although you may hide in any place ) I'll find you out.不论你躲到什么地方去,我都会找到你。 6用于由that, so that, in order that引起的目的状语从句。如 Try to help her so that she may catch up with us 尽量帮帮她,以便她能赶上我们。 work hard that we m