"En el tren."
Translation:In the train.
I put at the train to... a previous one said at the airport when it was en el auropuerto
I agree. If "en el aeropuerto" translates to "at the airport" than it perfectly fine to translate "en el tren" as " at the train".
No, thats where the app is difficult. En is used for in, at, and on. But english grammer doesnt allow "at the train."