Can a preposition come at the end of a passive voice construction?
Yes, it can. Note that the preposition will end the sentence only when the agent (thing or person who does the action) is not named.
One situation in which this can occur is when the active voice construction is verb + preposition + object.
Example:
Active voice: I looked at these reports.
Passive voice: These reports were looked at.
Another situation in which this can occur is when the active voice construction is + preposition + object.
Example:
Active voice: The criminal won't get away with this crime.
Passive voice: This crime won't be gotten away with.
The construction verb + noun + preposition + object is yet another that can end with a preposition when changed to the passive voice.
Active voice: People often made fun of the little boy.
Passive voice: The little boy was often made fun of.
Finally, note that an adverb can also come at the end of a passive construction when it is part of a . In this case the active voice construction is + object.
Example:
Active voice: Someone has put away the books.
Passive voice: The books have been put away.