Questions & Answers about Czy nie ma tu żadnych puszek piwa?
Why is the word for "cans" spelled puszek? Shouldn't we just drop the -a from puszka?
You are right that to form the Genitive plural of a feminine noun, we normally just drop the final -a. However, doing that to puszka would leave the hard-to-pronounce consonant cluster -szk. To fix this, Polish inserts a "fleeting e" between the final consonants, giving us puszek.
Why are we using the Genitive case for żadnych puszek?
The phrase nie ma (there is no / there are not) is a powerful trigger in Polish that always forces the missing thing into the Genitive case. Since we are stating that there are no cans, the phrase for "any cans" must take the Genitive plural form.
Is piwa also in the Genitive plural here?
No, piwa is in the Genitive singular. It translates to "of beer". We use the singular because we are talking about the uncountable substance (cans of beer). If you actually needed the Genitive plural to say "cans of beers", the neuter noun piwo would drop its final -o and become piw.
Why does the sentence use both nie and żadnych? Isn't that a double negative?