区别could,might,would,should have done

题目

区别could,might,would,should have done
作为虚拟语气could have done,might have done,would have done,should have done怎么区别

答案

要结合原形词义来理解
Can: 能……
Will：将/会……
Shall：应/应该……
May：也许……
肯定成份依次减弱,may是最不确定的语气.在虚拟语气里也是一样.
Could have done: 本来能……
Would have done：本来会……
Should have done：本来应该……
Might have done：本来也许……