He didn't buy anything yesterday.怎样变为被动语态.

问题描述:

He didn't buy anything yesterday.怎样变为被动语态.
如果变为:Anything wasn't bought by him yesterday.觉得别扭.
如果变为:Nothing was bought by him yesterday.原句子的结构变了.怎么变好呢?
Thankssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss.for your help!

Nothing was bought by him yesterday.
原句子的结构变了,如果是题目这样不算改变结构