Is it ok to say: "Az autó ott van, vagy a lány?" ...
No, the first half of the sentence should be a question also, as you put it, that would make it a statement.
Tx a lot. I understand.
'ott van az auto vagy a lány?' why is this marked as wrong?
See the answer from above (from BenceFerdinandy):
"No, the first half of the sentence should be a question also, as you put it, that would make it a statement."
Ez egy értelmetlen mondat!
I used "oda" instead of "ott." Why is that incorrect?
Oda means to there, specifying a direction.
But then I'm puzzeled, why is "Van ott az autó vagy a lány?" than wrong. The first half is now a queston (and no statement). The focus is now on the 'van ott' or 'is here', and not on the car. But DuoLingo marked it as wrong.
Ez nem jó, mert kérdő mondat.( Az autó ott van, vagy a lány van ott?) Ha kijelentő mondat akkor (Az autó van ott, és nem a lány)