Saying 'before' (I've done this before)

Saying 'before' (I've done this before)
 

I've read somewhere that if you want to say that you've been somewhere before, you could say something like "¿alguna vez has estado en Nuevo York?"
But what if I want to say something like "people have died before"? is it gramatically correct to say something like "las personas han muertos antes"?

Tycholiz, what's your native language?

before = antes

Now, on your first example I don't see either word... ;)

Maybe the context would tell if another kind of structure should be needed, but as I see it, there is only a small mistake you made to say what you mean. (See comments above.) :)

I don't understand, it's well documented that in spanish (as well as any other language) there are many occasions where a direct translation simply doesn't work. When translating word for word, it seems to me that simply saying "has estado en Nuevo York antes?" would trigger an answer such as "before what?" or "have a been to New York before _____?". This is where my confusion lay, so I'm just curious if it is gramatically correct to say "has estado en Nuevo York antes?", or to use antes in the same way for any other sentences where the word "before" is not followed by anything

Your "before what?" may be triggered if you say "¿Has estado antes en Nueva York?", but with "¿Has estado en Nueva York antes?" the meaning is univocal:

(Has estado en Nueva York) antes

(Has estado) antes en Nueva York

People have died before = Gente ha muerto antes It depends on what you want to say: Se sabe que la gente muere | Ya ha muerto gente (de esto/en estas circunstancias). "La gente ha muerto antes" makes no sense unless you are saying something like the atomic bomb blew after everybody has died because of the chemical weapons, and you are telling the story in "historical present".