Passive voice: He was thinking of where he had not searched

English as a Second Language English Vocabulary, Grammar and Idioms
1

Can we change the following sentence into passive like this?
“He was thinking of where he had not searched.”
“He was thinking of where had not been searched.”
Many thanks,
Morteza

2

Hi,

The passive sentence is just about possible but it is a bit of a stretch of the imagination to ask the reader to accept ‘where’ on its own. It would be better to say: 'of places/areas which had not been searched.

Alan

3

Hi,
Thank you so much.
Morteza

4

Hi Dear Alan,
Is “…of places where had not been searched.” correct?
I thank you in advance.
Morteza