朋友,情态动词表示推测的时候也是有被动语态的,就比如推测语气最强的Must,它的主动推测结构是:He must have broken into the house at night,这句话的被动推测结构就是:The house must have been broken into at night(这房子准是夜里有人强行闯入),再看你发的句子I think the classroom must be cleaned by students,我来给你改成被动推测结构:The classroom must have been cleaned by students,我改成了对过去情况的推测,因为我觉得学生打扫完教室,待你发现的时候,打扫教室这一举动已经过去很久了,希望能帮到你!
没有,情态动词本身就没有被动语态。
没有,比如must无进行无被动
好像没有
没有被动语态