"Sorry, do you stand up?"
There was a really good explanation somewhere, but let's try another one. When it is a yes-or-no type question, like this one, then the preverb does not get separated. Basically, the whole word is the focus of the question.
Btw., I would translate the Hungarian sentence differently:
"Bocsánat, felálltok?" - "Excuse me, would/will you stand up?"
So, "Do you stand up" is the same in Hungarian as "Will you stand up?" They seem different to me. The first is asking for information and the second is making a request. I would expect those to be different grammatically.
Well, if you give me a real life example of how would you use "Sorry, do you stand up?" to ask for information, maybe I can come up with an appropriate translation.
Let's call "Will you stand up?" an idiomatic meaning. And "Will you stand up?" itself, in English, is kind of idiomatic, too, isn't it? The literal meaning is just a question about the future, isn't it? So, why can't "Felálltok?" work the same way? Especially given the fact that a "sorry" is included, as well.
But a more accurate translation would probably be "Excuse me, are you going to stand up?"
That's how I thought of it, too ("are you going to stand up"). Because I need to get by you, and I can't while you're sitting down. Like in a movie theater when you're trying to get out of your row.
Or just: Are you going to stand up? Because I would like your seat if you are.
I can't think of a situation where "sorry, do you stand up" would make sense. You're asking someone if they stand up from time to time? Maybe if they're in a wheelchair, and you don't know if they can walk.
There is a way to make it look more like a real request, and it is to make it conditional.
"Bocs, felállNÁtok?" - Would you stand up?
Actually, this is asking more than one person if they would stand up - in all this discussion, I forgot about that.