Paulina explained that the"r"-sound in a word such as "gorzka", for example, is indeed pronounced, only not trilled:-)
No, I didn't!
I wrote: "In these words it's no longer "r", it's "rz", which is a compeltely different sound - you pronounce it like "ż"."
There's simply no
"r" in word "gorzka" - trilled or not trilled.
One should pronounce "rz" like "ż".
In fact, this "r", even to my non-native ears, is definitely audible, merely it elides, that is, it glides, into the consonant immediately following.
Audible? How on Earth can you hear "r" in here?:
Then again, as in any nearly every language, there will be regional or dialect pronunciations which vary from a consistent standard, Kraków vs. Warszawa, for example.
In general Polish language (the one you're taught at school and which most Poles speak) fricative rż (ř) turned in pronunciation into "ż" already in the 17th century. It was retained in some very few areas of Poland as this map shows:
However, even there such pronunciation disappears more and more rapidly and is spoken (rarely) only by older people.
One more link:
wiele spółgłosek miękkich zostało utwardzonych, np. miękkie r (zapis: r', np. r'eka - rzeka) przeszło w ż (zapis: rz).