情态动词+have done 如 could have done,must have done,should have done _英语解答

情态动词+have done
如 could have done,must have done,should have done 等等在如他么的否定词表示什么意思?

人气：199 ℃　时间：2020-03-16 07:48:39

解答

情态动词+have done 是一种虚拟语气,和情态动词+动词原形的区别是：用原型表示事情发生在现在或将来,而用have done ,表示事情发生在过去.例如,You must be tired now.（你现在一定很累）You must have seen the film...