用shouldn'thavedone表达 　　应该是cannothavedone和couldnothavedone吧 　　can/couldhavedone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/Couldhehavepassedtheexam?他可能通过了考试吗? 　　Ithinkthathecouldn’t/can'thavegoneabroad.Isawhimjustnow.我认为他不可能出国了.我刚才还看见他了.

　　是不是can'thavedone,canhavedone?都只表推测，而couldnothavedone和can'thavedone一样只表推测？