发布网友 发布时间:2024-01-13 03:25
共1个回答
热心网友 时间:2024-08-03 16:22
1、一个是被动语态,一个不是。
Have/Has been done是完成时态的被动语态
例如:the clothes have been washed already.衣服已经被洗了。
2、Have/Has done单纯的完成时态
1、“情态动词+have done”结构是高考重要考点,也是较难掌握的语法项目之一。
考点之一:在虚拟条件句中,如果表示与过去事实相反的情况,从句中用过去完成时,而主句中则用“情态动词+现在完成时”,即:would/ could/ should/ might have done。例如:
If they had finished the work on time, they would have been praised by the manager.
2、“must+have+done”表示对过去事情的肯定推测,译成“一定做过某事”,该结构只用于肯定句。
It must have rained last night, for the ground is wet. 昨晚一定下雨了,因为地面还是湿的。
You must have been mad to speak to the servant. 你和仆人说话,一定是发疯了。