后面跟to do的动词变被动语态是什么情况后跟不带to的不定式的动词变被动语态时要还原to,那么...还有跟doing的呢?例句 我问的是to 你们怎么理解的

to be done
to be doing

在主动结构中跟不带to的动词不定式作宾语补足语，在变为被动结构时，不定式应加上to。
We heard him say good-bye to his friends. 我们听见他向朋友们道别。
n He was heard to say good-bye to his friends. 他被听到向朋友们道别。
跟doing 的
being done

关于不带to的不定式,举个例子They did not observe she come in and go upstairs．被动：She wasn't observed (by them) to come in and go upstairs.带doing的就直接变换,因为doing的语法功能大体上相当于一个名词,...