Why is "This is the hat of a farmer" incorrect?
It's correct. Have you reported it?
No, unfortunately I didn't at the time when I was going through it.
it says "rolnika" is in the Dative, but here: https://en.wiktionary.org/wiki/rolnik, it says that this spelling is for the Accusative and the Genitive. Which information is right?
In this sentence, "rolnika" is in genitive case, in order to claim possession of the preceding noun, "kapelusz". :-)
'a farmer's hat' should be accepted
...and it is accepted.
seriously do farmers in Poland wear a special hat mainly for farmers? My grandfather to my GGG grandfather were farmers according to my genealogy tree
Shouldn't it be the genitive here (to express possession) ?
Two years too late, but it is genitive. "Rolnika". See https://en.wiktionary.org/wiki/rolnik and click on "Declension".
Is rolinka in genetive?
So what would have to be changed to make this sentence translate to "This is a hat farmer"?
Aaaaand... what does it mean?
A farmer that raises hats like they were corn maybe ;)
I wish I was a hat farmer