see sb doing sth 改成被动应该怎么改?比如I see mary playing the voilin.是Mary is seen to plying the voilin by me.

see sb doing sth 改成被动应该怎么改?
比如I see mary playing the voilin.
是Mary is seen to plying the voilin by me.

sb is/was seen doing sth
或者sb was/is seen to do sth
前者表动作,后者表状态

Sb.is seen doing sth某人被看到正在做某事.

楼主那道“比如”答案应该是
Mary is seen playing the voilin.
sb be seen to do sth
sb be seen doing sth
两者的区别是后者表示动作正在进行。