You get on ( and off) large means of transport which you can walk around inside : get on a train, a coach, a bus, a plane, a ferry. You get in ( and out of) small vehicles which you can't walk round inside: get in a car, a van, a taxi. That's how it is. One simple rule to remember. NB Remember that we also use on (and off) for means of transport that you literally have to mount : bike/bicycle, motorbike, scooter, moped, horse, camel, donkey etc.

Trains are higher than cars so you often step up when you are boarding it. Compare this with getting into a car where you have to sit down and "scrunch up" your body. It's helpful to learn the prepositions with their phrasal verbs, so: get in a car get out of a car get on a plane, a bus, a train, a tram, a trolley-car etc. get off a plane ... etc; Hope that helps! Lucie