need have done

来源:百度知道 编辑:UC知道 时间:2024/06/07 23:43:35
need have done , must have done , can/could have done , should have done 的区别是什么?意思是什么?主要用于哪种句型?请分别举例说明,谢谢!

need have done 。。。本人才疏学浅,没见过这种说法,通常是need to be done,表示需要被完成。如:All the housework needs to be done today. (今天需要完成所有家务。)
must have done肯定猜测语气,表示一定已经完成了。如:He must have finished the housework.(他肯定已经完成家务了。)
could have done 表示本可能已经完成某件事,常表示结果与事实相反。can have done 不常见。如:He could have finished the housework if he didn't watch the basketball games.(如果他不看篮球赛,本应该已完成家务了。)
should have done,应该已经完成某事,这个“应该”不是指推测,而是指理论上的,或义务上的。如:According to the cookbook,the cake should have been baked well now. (根据菜谱,蛋糕应该已经被烤好了。)