"Perish" is an intranstive verb. It does not take an object. To use passive voice, you need a transitive verb. Therefore you cannot say "the passengers were perished", b

It is fine to say, "The passengers perished."

However you can say, "The apples were perished." The reason is that "perished" is an adjective in that sentence, not a passive verb.

"Perish" is an intranstive verb. It does not take an object. To use passive voice, you need a transitive verb. Therefore you cannot say "the passengers were perished".

However you can say, "The apples were perished." The reason is that "perished" is used like an adjective in that sentence.

You can also say, "The passengers perished." The reason is that "perished" is used in active voice in that sentence.