should have done和could have done有什么不同？
二者都是虚拟语气，区别在于含义的不同。
1、should have done意为“过去本应该做某事却未做。”，表达一种责备或内疚的语气。
2、could have done意为“过去本能够做某事却未做。”，表示对过去事情的假设。
3、could have done还可以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。
4、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，should 比 could可能性要大。
例句：
①He could have looked over the papers in less than ten minutes.
他本可在10分钟内把文件翻看一遍的。
②If I'd waited in for you I could have waited all day.
要是我真留在家等你，那早都等上一整天了。
③He should have stuck to his guns and refused to meet her.
他本应坚持己见，拒绝与她会面。
④The night shift should have been safely down the mine long ago.
上夜班的矿工应该早就安全地到达井下了。
⑤I don't think we should have been there in the first place.
我认为我们从一开始就不该在那儿。
扩展资料
相关句子：
①I don't think we should have been there in the first place.
我认为我们从一开始就不该在那儿。
②The competition should have been rescheduled for a later date.
比赛本应另择日期。
