on or in is correct?

[Ganesh]

When my son was going on the train i called him .....He said I am going on the train
or in the train which is correct

on or in is correct?

rect?please give me a direct answer

[Torsten]

I called my son when he was on the train.

TOEIC short conversations: Withdrawing money from an ATM

[Kisco]

We use 'in' for the vehicle you need to squeeze in, like in the car, in the taxi. And we use 'on' for bigger vehicles, like on the plane, on the bus, on the ship, on the train.

Am i right?

[Haihao]

I'd think "on" is used for vehicles and vessels formed chiefly of a board.

[Blue_Snow]

I think on is the correct preposition as we must somewhat "climb" to get on a train, bus or ship but just need to get directly in a car or taxi

[Haihao]

"climb" is more related to "up", "down", and "to" than "on".

[Blue_Snow]

Yes. That why I put it in quotes and said SOMEWHAT. Just to some extent, not quite sure as I didn't know how to express my thought properly.