"I have never been here before."
Translation:Nigdy wcześniej tu nie byłem.
"Nigdy wcześniej [tu/tutaj] nie był[em/am]" sounds the best to me.
"Nie był[em/am] [tu/tutaj] nigdy wcześniej" also sounds perfectly natural, maybe a bit more emphatic.
"Nigdy nie był[em/am] [tu/tutaj] wcześniej" doesn't sound that great to me, but it seems fine. (edit almost 3 years later - frankly, it's weird. See below.)
"Nigdy [tu/tutaj] wcześniej nie był[em/am]" also sounds fine I guess, but I'd recommend using "tu" and not "tutaj" for better flow.
So... yeah, for this sentence it seems pretty flexible.
An adverb is not very likely to end up at the end of the sentence, and this particular one would be really weird. The last word is usually the new information, and "I have never been here BEFORE"... well, when else if not before? If it's past tense, then it's the only option.
The difference that I see between this and "Nie był[em/am] [tu/tutaj] nigdy wcześniej" is that "nigdy wcześniej" is treated as a whole here, and for "Nigdy nie był[em/am] [tu/tutaj] wcześniej" - frankly, I wouldn't agree with what I wrote almost 3 years ago in the comment above and I wouldn't say that it's fine ;)
Yes, it should.
I've seen similar comments and I have no clue what is going on. The sentence in the database uses "byłem", there shouldn't even be an audio file for "Nigdy wcześniej tu nie byłam". Perhaps that's a mix of a known bug with some other, still not clear behavior... right now I made "Nigdy wcześniej tu nie byłem" the only 'starred' answer, perhaps this will fix the problem.