[北师大版]高中英语一轮复习讲练精品：Part-II-语法部分-专题11-

专题十一 情态动词和虚拟语气

情态动词 一、定义

情态动词表示说话人对某一动作或状态的态度。 二、特点 1．有一定词义；

2．不受主语人称和数的变化影响；

3．与主要动词的原形(或称不带to的不定式)一起构成谓语(除ought to作固定词组看待)。 情态动词无人称和数的变化， 情态动词后面跟的动词需用原形，否定式构成是在情态动词后面加 “not”。 个别情态动词有现在式和过去式两种形式， 过去式用来表达更加客气， 委婉的语气， 时态性不强， 可用于过去，现在或将来。情态动词属非及物动词，故没有被动语态。

基本助动词与情态助动词最主要的区别之一是，基本助动词本身没有词义，而情态助动词则有自己的词义，能表示说话人对有关动作或状态的看法，或表示主观设想。 三、用法 1．can (could)

Everyone here can speak English. (表能力) He can't / couldn't have seen her there. (表猜测) He could have gone home. (表猜测) Could / Can I use your pen? Yes, of course you can. (表允许)

How can you be so careless? (表怀疑、惊异，主要用于否定、疑问句) Can / Could you lend me a hand? (表委婉发表观点) 2．may (might)

You may take whatever you like.(表允许，证据更委婉)

注：在回答以may引起的问句时，多避免用这个词，而用其他方式，如Yes, please. / Certainly. / Please don't. / You'd better not. / No, you mustn't.等，以免显得太严谨或不客气。 They might be having a meeting, but I'm not sure. (表可能) 3．must

You must buy a ticket. (表义务，意为“必须”)

注：回答Must...? 引出的问句时，肯定回答用must; 否定回答不能用mustn't, 而要用needn't或don't have to。

—Must I finish my homework now?

—Yes, you must.(No, you needn't / don't have to.)

This must be Lucy's. (表猜测，意为“想必；准是；一定”等，用于肯定) “must have ＋ 过去分词”表示“想必”之意，表示对过去的事情的推测。 4．shall

Shall I play soccer after supper? May I play soccer after supper?

If you don't behave yourself, you shall be punished. 5．will

I will do anything for you. 我愿为你做任何事。 (表意愿，用于各种人称陈述句) Will you give me a cigarette? Or I will tell the boss.(表请求，用于疑问句) She will stand there sleeping for hours. (表示某种倾向或习惯性动作) 6．should

You shouldn't be so careless. (表义务，意为“应该”，用于各种人称)

They should have arrived in Beijing by this time. (表推测，意为“想必一定、照说应该、估计”等)

It is simply a miracle that rice should grow in such a place. (表示语气较强的意为“假设；万一；竟然”) 7．would

I said I would do anything for you. (表意愿)

Would you please tell me the way to the nearest bus stop? (表委婉地提出请求、建议或看法) When he had a problem to solve, he would work at it until he found an answer. (表过去反复发生的动作或过去的一种倾向) 8．ought to

I really ought to phone my mother.(表义务，意为“应该”，口气比should稍重)

There's a fine sunset; it ought to be a fine day tomorrow. (表推测，暗含很大的可能，语气较弱) 9．used to

There used to be a building at the street corner, but it has been pulled down. (表示过去的习惯动作或状态，现在不再发生或不复存在) I usedn't / didn't use to smoke. (否定式)

Used you (Did you use) to go to school on foot? (疑问式) 虚拟语气 一、定义

虚拟语气表示说话人的愿望、假设、猜测或建议，而不表示客观存在的事实。虚拟语气通过谓语动词的特殊形式来表示二、用法

1．虚拟语气用于非真实条件句中，一是在if条件状语从句中；二是在含蓄虚拟条件句中，通过with, without, but for和动词不定式短语等表示虚拟的条件或句中含有or, or else, otherwise, but等词语，暗示句子的某一部分(前句或后句)需用虚拟语气。。 条件状语从句 主句 should / would / could / might ＋ have ＋ 过去分词 would / should / could / might ＋ 动词原形 与过去事实相反 had ＋ 过去分词 与现在事实相反 一般过去时 (be用were) 一般过去时或(should would / should / could / might 与将来事实相反 / were to) ＋ 动词原＋ 动词原形 形

If I were you, I would go with them. 假若我是你，我就同他们去。

If it hadn't been for your assistance, we wouldn't have succeeded. ＝ But for your assistance, we wouldn't have succeeded. ＝ Without your assistance，we wouldn't have succeeded.要不是你的帮助，我们就不会成功了。

If I asked him, I'm sure he'd help us.如果我向他提出要求，肯定他会帮助我们。

注意：错综时间虚拟条件句，即条件从句与主句所指时间不一致，如从句指过去，而主句即指的是现在或将来，此时应根据具体的语境情况，结合上面提到的三种基本类型对时态作相应的调整。

If it had rained last night, the ground would be wet now. 要是昨晚下过雨的话，现在地面就会是湿的。

You would be much better now if you had taken my advice. 假若你当时听我的话，你现在就会好多了。

2．虚拟语气用于主要是表示命令、要求、建议的动词后的宾语从句中。常见动词：一个坚持：insist；两个命令：order, command；三个建议：advise, suggest, propose；五个要求：demand, require, request, desire，ask。这些动词后面的宾语从句要使用虚拟语气用法。即从句中的动词使用should ＋动词原形，或者将should省略。

Mr Johnson insisted that the problem worthy of attention (should) be discussed at the meeting. 约翰森先生坚持应该

在会议外讨论这个值得注意的问题。

He urged that they go to Europe. 他敦促他们到欧洲去。 He suggested that we should leave early. 他建议我们早点动身。 He ordered that it (should) be sent back. 他命令把它送回去。

注意：insist作“坚持说；强调”解时，宾语从句不用虚拟语气；只有当insist作“坚持(应该)”解时，宾语从句才用虚拟语气。

The stranger we caught insisted that he had never stolen anything. 我们抓住的那个陌生人坚持说他什么东西也没偷。

3．虚拟语气用于wish后的宾语从句中，表示不能实现的愿望，意为“可惜……；…… 就好了；悔不该……；但愿……”等。表示现在不能实现的愿望，从句的谓语动词用过去式；表示将来不能实现的愿望，用“would (could)＋动词原形”；表示过去不能实现的愿望，用“had ＋过去分词”或“(could) would have＋过去分词”。

She wished she had stayed at home. 她后悔的是她当时要是留在家里就好了。(与过去相反) I wish you would go with us tomorrow.要是你明天同我们一起去就好了。(与将来相反) I wish I were you. 我要是你就好了。(与现在相 …… 此处隐藏：4226字，全部文档内容请下载后查看。喜欢就下载吧 ……