情态动词后接完成时态

问题描述:

情态动词后接完成时态
所表达的虚拟意义是怎么回事?谢谢

表示和过去相反的:shoule have done过去本应该做而没做的eg.You didn`t pass the exam.You should have studied hard last year.might have done过去本可以做而没做的eg.It was dangerous for you to climb to the t...