On the train? In the train? Or in trains?
"You are not supposed to eat in the trains." Is it possible to say on the train? Or in the train?

Question

On the train? In the train? Or in trains?
"You are not supposed to eat in the trains."  Is it possible to say on the train? Or in the train?

Answer

You are not supposed to eat in trains. (without the)
You are not supposed to eat on the train.    These two I would use in general conversation.
You are not supposed to eat in the train.  - I would only say this if I was on the train an saw someone eating.

Answer

in the train