could have done:本可以做却没做某事，强调“本来可以”；
might have done: 可能已经作了某事，强调猜测。
前两个都是假设，是与实际情况相反的假设。第三个是猜测。除此之外，should have done还明显含有懊悔或责怪之意。
举例来讲：
小明把家里的钥匙放在教室忘记带了。回到家打不开门一直蹲在门口等到晚上10点多加班的爸爸妈妈回来，很晚才进了家门。此场景下
1. 小明到家后发现钥匙忘带很懊悔。此时他可能会抱怨自己：I should have brought the key with me.
2. 那时的小明除了在门外等待爸爸妈妈回来，还有别的解决方案却没做：He could have come back to school to get the key but he didn't.
又如，当爸爸妈妈那么晚回来发现小明在门外，问明原因后，爸爸妈妈问他为什么当时不返回学校拿钥匙。爸爸妈妈认为若小明当时返回学校拿了钥匙的话可能早就进去了。爸爸妈妈可能会说：You could have come in much ealier if you came back school to get the key then.
3. 关于为什么当时没有返回学校拿钥匙，小明解释到：I thought the gate might have already been closed by that time.(学校大门那时候可能早已经关了）
For your reference. Tks!
could have done 是当初能（有能力）做某事但没做的
might have done 是可能做过了某事（表不确定）
should have done ;could have done; might have done 有什么区别
should have done:本应该做而没做某事，强调“本来应该”；could have done:本可以做却没做某事，强调“本来可以”；might have done: 可能已经作了某事，强调猜测。前两个都是假设，是与实际情况相反的假设。第三个是猜测。除此之外，should have done还明显含有懊悔或责怪之意。举例来讲：小明把家...
...could have done,should have done分别表示什么意思?
1. should have done 表示“过去本应该做某事却未做。”其否定结构 shouldn't have done 表示 “过去本不该做某事却做了。”2. ought to have done 表示“过去本应该做某事却未做。”其否定结构 oughtn't to have done 表示 “过去本不该做某事却做了。”3. need have done 表示“过去本有...
虚拟语气could\/should\/would\/might +have done 用法的差别?麻烦解答一...
could have done本来能够做什么，事实上没做 should have done本来应该做 would have done将来可能做 might have done可能做了 1. 很可惜你没做那件事，事实上你能够做的，所以选C 2. might as well 做什么更好，既然我无事可做，还不如跟着你好了 3. B， 对将来时的虚拟，他可能会迟到，告...
虚拟语气could\/should\/would\/might +have done 用法的差别?麻烦_百度...
1. "Could have done" 表示的是过去有能力或机会做某事，但实际未做，带有遗憾的语气。例如，"很可惜你没做那件事，事实上你能够做的，所以选C"，这暗示了一个未实现的可能性。2. "Should have done" 则强调过去本应做某事但未做，通常带有责备或后悔的情绪。"B， 对将来时的虚拟，他可能会...
could have done 和 might have done 的区别
could have done 和 might have done 的区别主要表现在两个方面：语气和语义适用范畴。could have 和 might have 是英语表达“虚拟语气”的常用方式。所谓“虚拟语气”（the subjunctive mood）是指用复合谓语（情态动词+助动词+实义动词）表达与已经放生的事情结果不同的可能性推断和说话者的情绪。用 ...
should\/could\/must\/might have done用法?
could have done表示本可以做而没做 must have done表示对过去事实的肯定判断，语气较重，即很肯定 might have done=may have done对过去事实的肯定猜测，语气较轻 eg.1.You should have swpet the floor.你本该扫地而没扫。（含责备语气）2.She could have done better.她本来可以做得更好的。
必修三英语语法,should have done ,could have done,might,m
could have done 是虚拟语气，表示对过去事情的假设，意思是本来能够做某事而没有 He could have passed the exam, but he was too careless.本来他能够通过考试，但是他太粗心。might have done 表示对过去事情的推测，might与may意思相同，但可能性更小。多用于虚拟语气结构中。She might have ...
为什么是could have done而不是should have done?
could have done与might have done相似，都是“可能、或许、也许”，肯定的推测意味不是那么强，弱于must have done，可以表示主观想象中的推断；而should have done目前的高考英语中的讲法是“不应该做某事（而实际上却没有做，可以有责备的语气意味）”。所以本题答案可以是could (或might) have ...
could have done 和 might have done 的区别
could have done 1.本可能做.,而实际上未做； 2.有可能做过某事,可能性较大 might have done 有可能做过某事,可能性较小.would have done 常用在虚拟语气中，表示对过去情况的虚拟，意为会做某事，其实未做； should have done 结构也是一种虚拟，表达一种责备或内疚的语气，意为，本应该做某事...
could have done 和 might have done 的区别
一、含义不同 could have done 本能够做 might have done 过去可能做 二、用法不同 could have done could (不能用 can) have done 表示“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...
