2023年Unit Sports events情态动词II知识梳理.doc

Unit 2 Sports events情态动词（II）概念引入Such things ought not to be allowed. 这类事不该容许He said I ought to write an article about it. 他说我应当写一篇文章谈这事I ought to be fit for work next month. 下个月我想必可以工作了I don’t think you ought to have done that. 我想你不应该这样做的 上一单元我们学习了英语中的大部分的情态动词，本单元我们会重点学习ought to的用法，并小结一下表示推测的情态动词，及三个用法与情态动词的相同的短语had better，used to和would rather语法讲解ought to的用法讲解1. 与众不同的ought toought to是一个比较奇怪的情态动词，因为其他所有情态动词都后接动词原形，而ought to虽然也是后接动词原形，但却无意中构成了ought to do sth结构，其中的to do sth.便是一个典型的带to不定式，并且ought to do sth在用法上也是基本上将ought与to do sth分开使用——如构成疑问句，只需将ought提前，而不是将ought to提前；构成否定式时，是在ought后面加上not，而不是在ought to的后面加not。

如：Ought I to tell her the truth? 我应该把真实的情形告诉她吗？We ought to be careful，oughtn’t we? 我们应该小心，对吧?Oughtn’t he to see a doctor? 他是不是该去看医生?You oughtn’t to stay out so late. 你不应当在外面待到这样晚在美国英语中，ought to用于否定句和疑问句时可将其中的to省略如：Ought we (to) have done it? 我们本该做此事吗?但是，肯定句中的to通常是不会省略另外，在简略答语中，有时也可以省去to如：—Ought he to go with us? 他应该同我们一起去吗?—Yes, he ought (to). 对，应该一起去2. 具体用法1. (表示义务、责任等) 应当，应该（与should同义，语气稍重）You ought to work harder than that. 你应该比那更加努力2. (用于劝告、建议等) 应该，该 You ought to start at once你应该立刻出发Such things ought not to be done.这种事不应该干。

3. (表可能性) 总应该，理应Mary ought to be home by now.玛丽这会儿该是到家了There is a fine sunset. It ought to be a fine day tomorrow.今天有晚霞，明天应该是个好天It ought to be a fine day tomorrow morning.明天旱晨大概是个好天气4. “ought to + have + 过去分词”表示过去应做某事而实际未做You ought to have told me about this earlier.(But you didn't)你本来应该早一点把此事告诉我但没有）I ought to have written that letter yesterday.(But I didn't)我本应该昨天写那封信但我没写）It ought to have been done long ago.这事早该做完的5. 4.Ought to 在间接引语中表过去时形式不变，如：He said you ought to tell the police. 他说你应该去报告警察3. 形式梳理：（1）否定式：ought后直接加not，可缩写为oughtn't。

One ought not (oughtn't) to cross the street against the red light. 不应该闯红灯过马路2）疑问式：把ought提到句首—Ought we to do it at once? 我们应该立刻做吗？—Yes, you ought to. 是的 （3）反意疑问句：下面两种形式都可以：He ought to be here now, shouldn’t (oughtn’t) he? 他现在应该在这里，是吧？should和ought to的区别1. 两者常可换用，ought to语气稍重You shouldn’t / oughtn’t to speak to your mother like that.你不应当这样和你妈妈说话2. 表示出于法令规则、行为准则、道德责任等客观情况而“应该”做某事时，常用ought toSuch things ought not to be allowed. 这类事不该容许You are his father. You ought to take care of him.你是他父亲,应该照顾他3. 表示主观看法、建议、劝说或表示某件事宜于做时，常用should。

You should listen to the doctor’s advice if you want to recover soon.如果你想很快康复，就应该听医生的劝告We should not use too many big words in our everyday speech.在日常生活中我们不宜于用太多的大词汇4. ought to更多反映客观情况，表示“有义务”或“必要”做某事You don’t look well. You ought to go to see the doctor.你气色不好，应该去看病5.should可以用于虚拟语态或状语从句中，而ought to 不能If I were you, I should try to get there before five.如果我是你，我会设法五点前到达那里Carol Harvey suggests that cyclists should be asked to ride on their own lanes. 卡罗尔·哈维建议骑自行车的人应该被要求在自己的车道上骑车6. should可以是shall的过去式，尤其在间接引语中，用于第一、三人称，以征求对方意见。

He asked me if he should get his visa tomorrow. 他问明天能否拿到签证7. should可以表示说话人的特殊情感，如惊奇、愤怒、失望等 I’m sorry that this should have happened. 我很遗憾竟然发生这种事I’m surprised that he should say so. 他竟这样说，这使我很惊讶Why should you think that way? 你为什么会那样想？must, have to和should／ought to表示的不同语气 钢琴老师对某学生说： You must practice at least an hour a day. (must 显示了老师的权威) 这个学生然后对他的朋友说：I have to practice an hour a day! (have to表示我本身不想练，但迫于老师的压力或者想学会的需要，不得不练) 他的朋友会说：You ought to／should practice for more than an hour. (表示不是来自外界的权威或压力，而是来自平辈同学或朋友的建议或者有义务做。

)易考点：表示推测的情态动词 1. 肯定推测: 用must, may, might注意：must/may/might have done 一定/可能已经做过（表示对过去的推测）He must be the new teacher. 他一定是那位新老师They must have come from Shanghai. 他们一定是上海来的They may/might have had a cold. 他们可能感冒了补充例句：He may /might tell his brother, but I am not sure. 他也许会告诉他弟弟，但是我不确定He must have sensed that I was looking at him. He suddenly glanced at me and said quietly, “Why are you staring at me like that?” 他一定是感觉到我在看着他他突然看向我轻声问：“你为什么那样盯着我看？”2. 否定推测：cannot 不可能cannot/couldn’t have done 不可能做过某事She cannot be his daughter. She is too old. 她不可能是他的女儿，她年龄太大了。

They cannot/couldn’t have caught the 9:15 train, for they left the hotel at 9:20.他们不可能赶上9：15的火车，因为他们9：20才离开旅馆He can’t have heard us. Knock again. 他不可能听见了再敲敲门3. 否定推测：may/might not 可能不He may /might not believe you. 他可能不会相信你4. 疑问句推测：can/couldWhat can /could they be doing? 他们会在干什么呢?Why does he know this? Can /Could someone have told him about it? 他怎么知道? 会是哪个人告诉他了吗?5. can也可以用于肯定句中，表示理论上的可能性(但实际未必会发生)，或表示“有时”Even experienced teachers can make mistakes. 即使是有经验的教师也可能出错She can be very unpleasant. 她有时很令人讨厌。

其他情态动词1. had better 最好1）had better + 动词原形2）否定形式：had better not注意：had better虽然有had，但不表示过去，而是指现在或未来，用于向对方提出劝告或警告You had better give up smoking. 你最好把烟戒掉 You had better not throw it on the ground. 你最好别把它扔在地上 2. used to 过去常常1）used to表示过去的习惯动作或状态，现在已不存在I used to get up early and take an hour's walk before breakfast.我过去常常起床很早并且在早餐前散步一小时2）在间接引语中，其形式可不变He told。