genitive. The most obvious use of genitive is "of something" or "someone's", but it is also used after certain verbs and prepositions, often with numerals, and in most negative sentences.
We really need some guidance on declensions! I thought I may have cracked it by cheating and looking up noun declensions on wiki, but the tables shown as templates there are totally different from what is in use here!!
What exactly is different? The English Wiktionary table for "papier" is correct.
I looked general guidance on noun declension and there was a set of tables, but the endings don't match, and some of the words are also different (e.g. dziewczyna, chłopak instead of chłopiec). Oh, confusion! Probably serves me right!
General guidance may be... too general. One learner recently found a mistake in Wiktionary tables, caused by something wrong in templates. Better to check specific words, I guess (although of course true, some generalization is very useful).
If you haven't seen it yet, this website maybe has some small mistakes sometimes, but it generally is pretty awesome: http://mowicpopolsku.com/
"dziewczyna" and "chłopak" are the more 'adult' versions for "girl" and "boy".
I don't think so, googling "card of paper" doesn't show anything like "kartka papieru" which is probably just a normal A4 sheet
Would this specifically and exclusively be a "sheet of paper"? Would "Kawałek papieru" mean something different?
That does sound like a piece of paper without any particular shape. Like, you just tore a part of the sheet to write down someone's number.
How would you say a paper card (like an index, business or greeting card)?
Index card: karta katalogowa fiszka
Business card: wizytówka
Greeting card: kartka z życzeniami kartka okolicznościowa
(Translations from English-Polish Dictionary by Dictamp)