情态动词用法

1 在虚拟语气中的用法 1 should have done 过去本应该做某事却未做 shouldn t have done 过去本不该做某事却做了 2 ought to have done 过去本应该做某事却未做 oughtn t to have done 过去本不该做某事却做了 3 need have done 过去本有必要做某事却未做 needn t have done 过去本没必要做某事却做了 4 could 不能用 can have done 过去本能够做某事却未做 注意 其否定形式 couldn t have done 没有虚拟语气的用法 couldn t have done 只能表推测 相当于 can t have done 意为 过 去不可能做了某事 5 might 不能用 may have done 过去本可以做某事却未做 注意 其否定形式 might not have done 没有虚拟语气的用法 might not have done 只能表推测 相当于 may not have done 意为 过去 可能没有做某事 二 表推测的用法 1 must have done 表示对过去某事的肯定猜测 译为 过去肯定做了某事 不存在 mustn t have done 的形式 其否定或疑问形式须用 can could 来表 示 例如 Since the road is wet it must have rained last night 既然路是湿的 那 昨天晚上肯定下雨了 He can t have missed the way I drew him a map 他不可能迷路 我 当时 给他画了张图 The dictionary has disappeared Who could have taken it 词典不见了 过去 谁可能把它拿走了 2 may might have done may might have done 表示 过去可能做了某事 may 比 might 表 示的可能性在说话人看来稍大些 may might not have done 表示 过 去可能没有做某事 例如 I can t find my keys I may might have left them at the school yesterday 我找不到我的钥匙了 我可能昨天把他们落在学校了 John may might not have passed the exam he looks very sad 约翰可能 没有通过考试 他看起来很忧伤 注意 may might have done 表推测不能用于疑问句中 3 can could have done 表推测一般用在否定句和疑问句中 表示不 相信或怀疑的态度 Can Could he have passed the exam 他可能通过了考试吗 I think that he couldn t can t have gone abroad I saw him just now 我认 为他不可能出国了 我刚才还看见他了 注 表示推测过去某动作发生的可能性时 就表示的可能性程度而 言 must 最大 could 其次 may 更次之 might 最小 例如 英语里形容词的比较级有三个等级 原级 positive degree as 原级 as 如 I m as tall as my twin brother 我和我的双胞胎哥哥一 样高 比较级 comparative degree 比较级 than 如 My father is younger than my uncle 我的父亲比我的 伯父年轻 最高级 superlative degree The 最高级 1 Sorry I m late I have turned off the alarm clock and gone back to sleep again 2000 北京春季 A might B should C can D will 答案为 A 表推测的用法 句意 对不起 我迟到了 我 当时 兴许是关了闹钟又回去睡觉了 might 相当于 may 但语气更加不 肯定 2 I was really anxious about you You home without a word 01 全国 A mustn t leave B shouldn t have left C couldn t have left D needn t leave 答案为 B 虚拟语气用法 句意 我 那时 真地很担心你 你本 不应该不留个话就离开家 3 I ll tell Mary about her new job tomorrow You her last week 04 福建 A ought to tell B would have told C must tell D should have told 答案为 D 虚拟语气用法 句意 我明天要告诉她我的新工作的 情况 你本应该上周告诉她 4 Tom graduated from college at a very young age Oh he have been a very smart boy then 04 全国 IV A could B should C might D must 答案为 D 表推测的用法 句意 汤姆很年轻的时候就大学毕 业了 哦 他肯定是一个很聪明的男孩儿 5 He have completed his work otherwise he wouldn t be enjoying himself by the seaside 05 北京卷 A should B must C wouldn t D can t 答案为 B 用法同 4 题 句意 他肯定做完了工作 不然他就不会 在海边痛快地玩儿了 6 Do you know where David is I couldn t find him anywhere Well He have gone far his coat s still here 05 湖北卷 A shouldn t B mustn t C can t D wouldn t 答案为 C 表推测的用法 句意 你知道大卫在哪儿吗 我哪儿 也找不到他 瞧 他不可能走远 他的上衣还在这儿呢 can t 相 当与 couldn t 但后者语气更加委婉 四 练习 1 The woman biologist stayed in Africa studying wild animals for 13 years before she returned Oh dear She a lot of difficulties 05 江苏卷 A may go through B might go through C ought to have gone through D must have gone through 2 I have lost one of my gloves I it somewhere 05 北京春 季 A must drop B must have dropped C must be dropping D must have been dropped 3 Mr White at 8 30 for the meeting but he didn t show up 04 广西 A should have arrived B should arrive C should have had arrived D should be arriving 4 He paid for a seat when he have entered free 05 山东卷 A could B would C must D need 5 Tom is never late for work Why is he absent today Something to him 05 江西卷 A must happen B should have happened C could have happened D must have happened 6 I have been more than six years old when the accident happened