"Nic o mnie nie wiesz!"

Translation: You know nothing about me!

[Metlieb]

Nic o mie nie wiesz, Jonie Snow!

[immery]

Nic nie wiesz Jonie Snow o mnie. - uncommon but correct.

[KornDog513]

So, when addressing some one you would put it in the middle of the sentance like that?

[Jellei]

That does seem quite unusual to me... and then you definitely need commas on both sides. I wouldn't recommend such an option.

[WellingtonCatnip]

A good way to remember will lock this phrase down

[Carlossynt]

Nic nie wiesz, John Snów!

[TurpinVro]

Is there something where i can better learn grammatical structures

[Jellei]

Well, I am slowly writing Tips & Notes (up to "Present 3: at the moment I'm writing it), you can also check www.mowicpopolsku.com or check this post https://forum.duolingo.com/comment/16296174.

[HermesLlain]

Why "anything about me" and not "nothing about me"? I thought "Nic" was "nothing" ot maybe it is but i do not difference.

[Jellei]

Actually, "You know nothing about me!" is the default answer, with "You do not know anything about me!" being just accepted. Yes, "nic" = "nothing", but the English and Polish grammar work very differently here (Polish requires double negation), so the translations often are quite different.

[joruki]

direct translation would be "Nic Wiesz, Jonie Snow" but is that unusual for native polish speakers?

[Jellei]

Not unusual, just wrong. Double negative is a must.

[Etuszyns]

why doesnt the negation make it niczego?

[Jellei]

"nic" and "niczego" are both proper Genitive forms, even though only "niczego" does seem Genitive at first sight. They are equivalent, although one or the other may sound better/more idiomatic in the given sentence.