should/ought to/might/ mustn't/cant't/need't/don't/could/ have done是哪类虚拟语气,非真实，情态动词，意愿成分，个别特殊，哪类虚拟语气
问题描述：
should/ought to/might/ mustn't/cant't/need't/don't/could/ have done是哪类虚拟语气,
非真实，情态动词，意愿成分，个别特殊，哪类虚拟语气
答
表示本应该做某事，而实际却没做。
例：She should not have bought the book.
她本不该买这本书，而其实她买了。
答
should have done表示主句对过去的虚拟
非真实 与现实相反