"Where can you have lunch?"
Translation:Hol tudsz ebédelni?
Oh, but maybe the confusion may come from the word "tudni". It is used for both "know" and "can" (be able) in Hungarian.
I can read. - Tudok olvasni.
The formula is "tudni" with conjugation plus a verb in the infinitive form.
When the verb has a preverb, then the conjugated form of "tudni" comes between the preverb and the verb:
El tudom olvasni.
Oda tudok menni.
Fel tudsz állni?
Meg tudjátok csinálni?
When these things are negated, then the "tud" part is negated and the verb fuses again:
Nem tudom elolvasni.
Nem tudok odamenni.
Nem tudsz felállni?
Nem tudjátok megcsinálni?
Ditto KrisWD's comment. Tudni is often glossed as "to know; to know how to do something". Knowing how to do something is a little like being able to do it -- but it's very different from "can", and it really didn't make sense in the context of the sentence "Where can you have lunch?"
Yes, OK. Well, it means both "to know" and "to be able to". I said it somewhere else: all meanings of "can" are not covered by "tudni" though! I would say as far as "can" can be replaced with "be able to", "tudni" also covers "can".
Meanings of "can" that are not covered have to do mostly with permission. As in "you can have it", "come on, you can't do that", etc. These are covered mostly by the "-hat"/"-het" suffix that you attach to the verb before the personal suffix.
"meg tudod csinálni" - you can (are able to) do it
"megcsinálHATod" - you can (may or are permitted to) do it
"Ezt nem csinálhatod velem!" - you can't do this to me!
"A tiéd lehet" - you can have it (literally: it can (is allowed to) be yours)
Replying here as we reached the bottom of the reply tree. Yes, that is correct, "tudni" is used for both.
I can say "nem tudok úszni", because I have never learned how to swim or because I do not have the time. Or because I broke my leg. The same way as you can say them all with "can".
And if you need to clarify what you are talking about, then you simply explain: I know how to swim but I don't have time right now. Or I broke my leg.
You can say "I can (am able to) swim, but I can't right now." Something like that.
"Tudok úszni, csak most nem tudok." - I can swim, only now I can't.
"Tudok úszni, csak nem érek rá." - I can swim, only I don't have the time. "Nem érek rá" is a common way of saying "I don't have time (right now)".
"Tudok úszni, de eltörött a lábam." - I can swim but my leg is broken.
ErikAnderson3 - sorry for the late reply. I would say this "tudni" thing is really ambiguous. Yes, there is an ability part of it, there is also a learned part of it, and there is a current condition part of it. "Tudni" can cover any and all of it. It depends on the actual activity, context, and who knows what else.
Yes, if my leg was broken, I could say "Nem tudok futni."
And how about this one: I can read (because I learned how to read) but I cannot read in the dark.
"Tudok olvasni, de sötétben nem tudok (olvasni)."
This is really quite as ambiguous as "can" is.
And there are some verbs where we don't use "tudni" at all. Or only in some specific meaning. Most importantly, with hearing and seeing.
"I don't/can't see/hear." - "Nem látok/hallok."
And this topic is even more complex, but those are really fine details, better learned in real life, talking to people.
(Oh, and I just realized that I had replied already. Oh well, this is another take on the same.)
Excellent additional detail, thank you. So tudó is both "knowing something" and "being able to do something, having the ability to do something". There is some overlap, in the sense of "knowing how to do something", but the underlying "ability" sense is separate from knowledge. Is that correct? For example, would you say "nem tudok futni" if your leg was broken?
First off, let's agree that having lunch is not a matter of ability anyway. Besides, the tud version sounds more practical. "I can organize my business so that we have lunch together" while the hat version is more like "nothing really contradicts this, there is a greater than zero probability, I'm allowed..." So, when you make an offer, you may go with the second, picturing the possibility, while if you were asked to do so, you may prefer the first, expressing that you can manage it.