would have done,could have done,should have done,need have done,must have done的用法及區別無

熱心網友

would have done本來要做的事卻因為什么事而耽擱沒有做,could have done本來能夠做的事卻沒做,should have done本來應該做的事卻沒做 ,need have done有必要做的事卻沒做,must have done一定做過某事

熱心網友

must have done對過去的推測would have done本來要做的事卻沒有做could have done通常用與否定,表示對過去時態的推測need have done通常用與否定,表示對做過的事沒有必要.這是我大四的時候老師講的