为什么这里不要还原to?I heard the boy singing just now.The boy was heard singing just now.

分类: 作业答案 • 2021-11-12 22:51:07

问题描述：

答

hear +宾语 +宾补[ do/doing/v+ed ]
hear +宾语 +do宾补此结构中是省略了to的不定式.当变成被动时才要还原to