must have done是什么意思?
must have done 是对过去发生的动作最有把握的猜测,意思是“一定”。
例如:走到门外看到地上湿的,便猜“刚才一定下过雨了”,英语就是 It must have rained. 把握差一点的用should;
例如地上不是太湿,你猜“刚才应该下过雨吧。” It should have rained. 把握再差一点的用may: It may have rained.“刚才可能下过雨”。 最不肯定的用might: It might have rained。
扩展资料:
must have done:表示对过去的肯定的逻辑推测,推定某件事情、动作或状态可能在过去发生过(存在过)。
He must have been a doctor,for he knows medicine so well.(他过去肯定是一位医生,他对医学如此了解。)
Somebody must have stolen the ring.(肯定有人偷了这枚戒指。)[该句所推断的偷窃动作发生在过去。]
The temperature must have dropped to below zero last night ,because the water is frozen all over.(昨夜的温度肯定降到零度以下,因为水都冻住了。)
如果'must + have + 过去分词'句型与by now连用,还可以表示对现在完成的动作和状态的肯定推测,但实质上还是指所推测的过去的动作,例如:
They started early this morning; they must have arrived by now.(他们今晨很早就出发了,现在肯定已经到了。)
中国学生的常见病句是:They…; they certainly have arrived.病句的句义是“他们当然已经到达了.”(这不是对过去的肯定推测,而是断定动作已经完成。)