情态动词主要包括can, could, may, might, shall, should, will, would, must, ought to, used to, need, had better/best, dare等，下面我们将借助词典学习常见情态动词的基本用法：
| 基本用法 | 示例 |
|---|---|
| Used to indicate physical or mental ability: 能，会：用于表示身体或精神上的能力。 | I can run fast. 我能跑得很快。 I can swim. 我会游泳。 |
| Used to indicate possession of a specified power, right, or privilege: 拥有权利：用于表示拥有某种特殊权力、权利或特权。 | The President can veto congressional bills. 总统有权否决国会提案。 |
| Indicating possibility 表示可能性。 | That can't be Mary--she's in hospital. 那不可能是玛丽--她住院了。 |
| Indicating requests 表示请求。 | Can you feed the cat? 你喂喂猫好吗? |
| Indicating permission 表示许可。 | Can I read your newspaper? 我能看看你的报纸吗? |
| Used to describe typical behaviour or state 用以描述特有的行为或情形。 | She can be very forgetful. 她这个人很健忘。 |
| 基本用法 | 示例 |
|---|---|
| Indicating possibility 表示可能性。 | You could be right, I suppose. 我想可能是你对。 |
| Indicating requests 表示请求。 | Could you baby-sit for us on Friday? 星期五你替我们照看小孩行吗? |
| Indicating permission 表示许可。 | Could I use your phone? 让我用一下你的电话好吗? |
| Indicating suggestions 表示建议。 | We could write a letter to the headmaster. 我们不妨给校长写封信。 |
| 基本用法 | 示例 |
|---|---|
| Indicating possibility 用以表示可能。 | It may rain today. 今天可能下雨。 |
| Indicating permission 表示许可。 | You may come if you wish. 你要来就来吧。 |
| Used to express contingency, purpose, or result in clauses introduced by that or so that: 用于由that 或者 so that 引导的从句中，表示可能、目的或结果。 | Write to him at once so that he may know in time. 立刻写信给他，好让他及时知道。 |
| Used to express a desire or fervent wish: 希望：用于表达愿望、祝愿。 | May you both be very happy! 祝你们俩幸福! |
| 基本用法 | 示例 |
|---|---|
| Indicating possibility 用以表示可能。 | We might discover a pot of gold at the end of the rainbow. 我们可能在彩虹的末端发现一罐金子。 |
| Used to make polite requests or appeals 用于婉转的请求或吁请。 | You might just (ie Please) call in at the supermarket for me. 请顺便为我去一趟超级市场吧。 |
| Indicating permission 表示许可。 | Might I ask a question? 我是不是可以提个问题? |
| 基本用法 | 示例 |
|---|---|
| Something, such as an order, a promise, a requirement, or an obligation: 表命令、要求、承诺或义务。 | She shall not enter my house again. 她不得再进我家。 Candidates shall remain in their seats until all the papers have been collected. 试卷全部收回后应试人才可离开座位。 You shall have an answer by tomorrow. 到明天你可以得到答复。 |
| Indicating offers or suggestions: 表示提供意见或建议。 | Shall I carry your bag? 我帮你拿手提包，好吗? Let's look at it again, shall we? 咱们再看一看好吗? |
| 基本用法 | 示例 |
|---|---|
| Used to say or ask what is the correct or best thing to do：应该，即表示做某事是正确的，或某事最好要做。 | Children should obey their parents. 儿童应该服从他们的父母。 The general director of the project ordered that the work (should) be started at once. 工程总指挥命令立即开始工作。 |
| Used to refer to a possible event or situation：可能，即表示某事可能发生。 | If you should change your mind, do let me know. 如果你改变主意, 一定要告诉我。 |
| Used to show something is expected：预计某事会发生。 | I should have finished reading it by Friday. 我大概到星期五能把它看完。 |
| Used to say that sth that was expected has not happened：表示预计发生的事，却没有发生。 | It should be snowing now, according to the weather forecast. 根据天气预报，现在应该正下雪的。 The bus should have arrived ten minutes ago. 公交车10分钟就应该到的。 |
| Used to say that sth was unexpected：表示未料到某事。 | That he should speak to you like that is quite astonishing. 他竟然这样对你说话, 实在让人吃惊。 Why should he think that? 他怎么那么想呢? |
| Used after so that/in order that to express purpose：用于so that/in order that之后表示目的或动机。 | He took his umbrella so that he shouldn't get wet. 他带了把伞以防淋湿。 |
| 基本用法 | 示例 |
|---|---|
| Used to show that someone is willing to do something：用以表示愿意做某事。 | He'll take you home--you only have to ask. 他愿意送你回家--你跟他一说就行。 Will you post this letter for me, please? 请您把这封信给我寄出去行吗? |
| Indicating present predictions：用以表示对目前事物的预料。 | This'll be the book you are looking for. 这可能是你正在找的那本书。 That will be the messenger ringing. 可能是送信的人在按铃。 |
| Used to indicate requirement or command: 用于表示要求或命令。 | You will report to me afterward. 你稍后要向我报告。 Will you be quiet! 安静点儿! |
| Describing general truths：用于叙述众所周知的事实。 | Oil will float on water. 油能浮在水面上。 |
| Describing habits in the present or past：用于叙述目前的或过去的习惯时。 | People will talk. 人们总是说三道四。 She will listen to records, alone in her room, for hours. 她独自一人在屋里听唱片，每每一听就是半天。 |
| Used to indicate capacity or ability: 用于表示能力或功能。 | This bus will hold 40 people. 这辆大客车可以坐40人。 |
| 基本用法 | 示例 |
|---|---|
| Used to show that someone is willing to do something：用以表示愿意做某事。（看成will的过去式，表示客气） | Would you pay me in cash, please? 请您付给我现金行吗? Would she like to borrow my bicycle? 她想借用我的自行车吗? I'd love a coffee. 我倒想喝杯咖啡。 |
| Used to give opinions that you are not certain about：用于表示不确定的意见。 | It would seem to be getting warmer. 天气似乎变得更暖和了。 I would imagine the journey will take about an hour. 我猜想这个行程大概需要一个小时左右吧。 |
| 基本用法 | 示例 |
|---|---|
| Indicating obligation：表示必要。 | We must obey orders. 我们必须服从命令。 You must not do it. 你不可以做那件事。 I must go to the bank to get some money. 我得到银行去取些钱。 |
| Drawing a logical conclusion：做出逻辑推断。 | You must be tired after your long journey. 你走了这么远的路，一定很累。 He must have earned a large sum of money. 他一定是挣了一笔巨款。 |
| To be determined to; have as a fixed resolve:下决心一定要；坚持要。 | If you must leave, do it quietly. 如果你一定要离开，那就悄悄地走。 Why must it rain on Sunday? 偏要在星期天下雨, 讨厌! |
| 基本用法 | 示例 |
|---|---|
| Indicating obligation：表示必要。 | You ought to work harder than that. 你应当更努力地工作。 There ought to be more buses during the rush hour. 高峰期间应该多开几趟公共汽车。 |
| Drawing a tentative conclusion：作推测性的结论。 | She ought to finish by next week. 下星期她该完成了。 Look at the sky--it ought to be a fine afternoon. 看看天--下午一定很晴朗。 |
| 基本用法 | 示例 |
|---|---|
| If something used to happen, it happened regularly or all the time in the past, but does not happen now: 表达过去经常的或持续的行为，但现在不再是。 | I used to live in London. 我过去一直住在伦敦。 We used to go there every year. 我过去每年都去那儿。 |
| 基本用法 | 示例 |
|---|---|
| Indicating obligation: 表示必要。 | They need not come. 他们不必来。 He wondered whether they need send a deposit. 他不知道他们是否得交定金。 |
| Used with have + a past participle to indicate that actions in the past were or may have been unnecessary: 与have +过去分词连用，表示曾做的事无必要。 | You needn't have spent all that money. 你本可以不花那么多钱的。 You needn't have washed all those dishes, you know - I'd have done them myself when I got home. 你本来不用洗那些碗碟的，你知道——我回家后自己会洗的。 |
| 基本用法 | 示例 |
|---|---|
| Had better/best：would be wise to 最好。 | We had better go before the storm becomes worse. 在暴风雨更大之前我们最好就走。 We'd better not invite him. 我们最好不要邀请他。 |
| 基本用法 | 示例 |
|---|---|
| Have sufficient courage or impudence to do sth: 敢。 | I wonder whether he dare stand up in public. 我不知道他敢不敢站在大庭广众面前。 They hardly dared breathe as somebody walked past the door! 有人在门前走过，他们几乎不敢呼吸了! |
| 对现在及将来可能性的推测 | 示例 |
|---|---|
| 在确信某事属实或认为这是唯一可能的现实情况时，使用 must。我们通过推理或查看证据得出这个结论。 | Harry's been driving all day -- he must be tired. 哈里开了一天车，他一定累了。 That must be Rachel's house. I can see her car outside. 那一定是瑞秋的房子。我能看到她的车在外面。 |
| 当确信某件事不可能时，使用can't。 | This can't be the right road. 不可能是这条路。 That can't be Mary-- she's in hospital. 那不可能是玛丽--她住院了。 |
| 使用 should 和 shouldn't 来表达对未来的期望，表示某事很可能会发生，因为从常理上看它是合理或正常的。 | My dry cleaning should be ready this afternoon. 我干洗的衣服今天下午应该洗好了。 Take this medication as prescribed and get plenty of sleep. You should recover from the flu in about a week. 按医嘱服用这种药物,并确保充足睡眠。你应该能在一周左右从流感中恢复过来。 Finding a parking spot downtown shouldn't be difficult. 在市中心找个停车位应该不难。 |
| 使用might、may或could来表示我们认为现在或将来某事是有可能发生的，但我们并不确定。它们的否定形式是may not 和 might not。couldn't表示某事不可能发生。 | I might come and visit you next year, if I can save enough money. 如果我能存下足够的钱，明年我也许会来看你。 Don't go any closer --it might be dangerous. 别再走近了--那可能很危险。 There may be other problems that we don't know about. 可能有我们不知道的其他问题。 A lot of crime could be prevented. 许多犯罪活动是可以防止的。 I'll try the pharmacy, but it might well be closed now. 我会尝试去药店，但现在很可能已经关门了。 |
| can表示一般可能性。 | You can get very nasty skin diseases from bathing in dirty water. 在脏水里洗澡会得严重的皮肤病。 It can be very hot here in summer. 夏天这里可能非常炎热。 |
| 对过去可能性的推测 | 示例 |
|---|---|
| 当我们确信某事已发生时，使用 must have +过去分词。 | When you got lost in the forest you must have been very frightened. 那天你在森林里迷路了，一定很害怕吧。 The thief must have had a key. The door was locked and nothing was broken. 那个小偷一定有一把钥匙。门是锁着的，而且没有任何破坏迹象。 |
| 当我们认为某事可能已经发生时，我们使用 might have 或 may have + 过去分词。could have 也可以表示类似含义。 | I think I might have left the air conditioning on. Please can you check? 我想我可能忘记关闭空调了。你能帮忙检查一下吗？ The explosion may have been caused by a faulty electrical connection. 爆炸可能是由电路连接错误引起的。 Police think the suspect may have left the country using a fake passport. 警方认为嫌疑人可能已经使用假护照离开了这个国家。 |
| 当我们认为某事不可能已发生时，使用can't have和couldn't have +过去分词。can't have语气更直接，couldn't have稍柔和。 | Lily can't have driven there. Her car keys are still here. 莉莉不可能开车去那里。她的车钥匙还在这里。 Anna can't have made dinner. The kitchen is spotless. 安娜不可能做过晚饭。厨房一尘不染。 I thought I saw William this morning but it couldn't have been him--he's in China this week. 我原以为今早看到威廉了，但不可能是他--他这周在中国。 |
单选：选择最合适的答案。
注：此处仅保留部分代表性练习，完整练习请参考纸质版或后续版本。