请问高手 MUST have been done

Question

must have been doing
must have been +名词
must have done
以上的区别
还有是否有must have been done 的用法 和区别
EG1 I must have been sleeping

2 your dress must have been expensive.

3 I didn't hear the phone, I must have been alseep

Answer 1

其实must have been done只是must have done的被动形式罢了。

我说，你举出来的那几个例子：1那个就是must have been doing的结构是指某动作在过去某时间点开始，一直持续到现在，有继续持续下去的趋向，或者等这句话一说完这个动作就完成；
2那个是加形容词 be expensive=很贵，must have been expensive= 一定是很贵的了。
3那个asleep也是形容词，be asleep=睡着的。句子意思是：那时我一定是睡着了。（表示对过去肯定的推测）

Answer 2

must have done是对过去事实的肯定猜测 而must have been doing 表示某人一定正在做某事 这个动作从过去持续到现在 must have been就是表示一个肯定的结果