高三情态动词（二）

① ought to表示“应该”,指道义上有责任或显示所采取的行动正确或明智,其否定式为ought not to, oughtn't to。如:She ought to look after her children better.她应该把自己的孩子照顾得好些。I wonder whether I ought not to speak to him about it.我不知道我该不该跟他谈一谈这件事。You ought to be more careful, you know.你该小心一点。Ought he not to see a doctor? 他不该去看看医生吗?

銆愯叮鍛宠嫳璇€戞槬鑺傚皬鐭� 涓栫晫鑺傛棩锛�1锛塖pring

② ought to和should 在意思上相近,但ought to的语气稍强。oughtn't 和shouldn't都可以用来对不正确或不明智的行为提出警告。“ought to have+V-ed”,表达“本应该……”。例如:You oughtn't to/ shouldn't talk so loud; you'll wake the baby.你不该这么大声说话,你会吵醒婴儿的。You ought to have / should have helped him.你本应该帮助他的。You oughtn't to have/ shouldn't have hit him.你本来就不该打他。试比较:needn't指“某事是没有必要的”,如:You needn't talk so loud; I can hear you.你用不着这么大声说话,我能听得见。

(6) shall, should

① shall和should用作助动词时,should是shall的过去式;用作情态动词时,二者意义不同。shall在正式文体中表达“必须”、“必将”、“许诺”,用于第二、第三人称。如:You shall do as you see me do.你照我的样子做。He shall be punished if he disobeys.他如不服从就要受处罚。Payment shall be made by cheque and the terms shall be as follows.可用支票支付,条件如下。

② should表达“有义务”、“有必要”、“可能”,与ought to意思相近。其否定式为should not, shouldn't。“should have+V-ed”,表达“本应该...”。如:If you see anything unusual you should call the police.你如果发现有不正常的情况,应该打电话给警方。He shouldn't have / oughtn't to have said that.他本不该那么说的。The photos should be ready by tomorrow morning.明天早晨照片有可能冲印出来。

③ 用于that引导的从句中,表达一定的感情和意见。如:I was anxious that our plan should not fail.我殷切希望我们的计划不致失败。I suggest that John should go/ that John go.我提议约翰去。They demanded that there should be an official inquiry.他们要求进行一次正式的调查。

(7) will, would

① will和would用作助动词时,would是will的过去式;用作情态动词时,will/would表达“意愿”、“请求”、“习惯”或“反复发生的动作”,其否定式为will not/ won't, would not/wouldn't。二者用法稍有不同。will指将来,would通常用于间接引语,指过去的将来。如:I won't argue with you.我不愿跟你争辩。I said I would do anything for him.我说过我愿意为他做任何事情。Will you dine with me tomorrow, Lewis? 刘易斯,明天你同我一道吃饭好吗? Would you mind closing the door? 请关上门好吗?John will fall asleep in church.约翰做礼拜时老睡觉。Most often we would find him lying on a couch, reading.我们经常看到他躺在长沙发上看书。

② would用于固定习语或习惯用法。如:I'd rather/ I would rather you didn't tell him.我倒宁愿你没告诉他。I'd rather not say what I think.我宁愿不说出自己的想法。You'd better/ You would better go by yourself.你最好自己去。I wish the rain would stop for a moment.我希望雨停一会儿。I wish they wouldn't insist on it.我希望他们不坚持那一点。

③ would和used to都可表示过去的习惯,但used通常指现在已没有此习惯的含义,并可表示一次性动作。如:When we were children we used to / would go skating every winter.我们小时候每年冬天都去滑冰。I used to have an old Rolls Royce (此处不可用would).我曾有过一辆旧的劳斯莱斯小轿车。

(8) need

① need 既可作情态动词,也可作实意动词。用作情态动词时,表示“有必要”,它只有一种形式,后跟不带to的不定式,只用于否定句(或含有否定意味的肯定句)和疑问句。因此,need问句的肯定回答应用must。“needn't have+V-ed”表示“过去本来不必做某事(却做了)”。用作实意动词时,它有动词的全部形式,即一般现在时单数第三人称needs,现在分词needing,以及过去式和过去分词needed,后跟带to的不定式,可用于一切句式。如:—Need we go so soon? 我们必须这么早就去吗?—No, we needn't.(—Yes, we must.)不,不必。(—是的,必须。)You needn't have gone there yesterday.你昨天不必去那儿。Did it need to be done so soon? 需要这么快就做它吗?

② 因为need可兼作情态动词和实意动词,所以,在疑问句中,既可说Need he study? ,也可说Does he need to study? ; 在否定句中,既可说He needn't study.也可说He doesn't need to study.;在陈述句中,need后面只能跟动词不定式:He needs to study.(他必须念书。)

(9) dare

dare 意为“胆敢,敢于”,既可作情态动词,也可作实意动词。用作情态动词时,它只有一种形式,后跟不带to的不定式,只用于否定句和疑问句。用作实意动词时,它有动词的全部形式,即一般现在时单数第三人称dares,现在分词dar-ing,以及过去式和过去分词dared,后跟带to的不定式,可用于一切句式。不过,作为实意动词和情态动词dare可以交叉使用。如:How dare you accuse me of lying!你竟敢指责我说谎!That is as much as I dare tell you.我敢告诉你的就只有这些。We all knew she was wrong, but none of us dared (to) tell her.我们都知道她错了,但我们没有一个人敢对她说。The government would never dare (to) in-crease taxes so soon before the election.在快要大选之前,政府绝不敢加税。