Is there any difference in meaning between the following sentences?
I have been standing up in the train a few hours.
I have standing up on the train a few hours.
Not a long time ago, I thought that the second sentence was the only correct, but then I saw in being used in the context in a textbook. If there is no difference, which one is more common. And by the way, do I have to use stand up in the context. Could I just say
I have been standing on/in the train a few hours?