Learn Polish: Popijam wino z kieliszka i słyszę, jak rośnie gwar. - I sip wine from a glass and hear the hubbub growing.

After verbs of sensory perception like słyszeć (to hear), widzieć (to see), or czuć (to feel), Polish uses jak to frame an ongoing action that you are actively witnessing. If you used że here, it would imply you are hearing about a fact (perhaps someone told you about the noise), whereas jak emphasizes that you are physically experiencing the noise increasing right now.

Could I say jak gwar rośnie instead of jak rośnie gwar?

Yes, it is grammatically correct, but jak rośnie gwar sounds more natural and literary. In Polish, placing the subject at the very end of the clause often serves to introduce the most important new information (the focus). It builds a slight sense of atmosphere, emphasizing exactly what it is that is growing.

What is the difference between popijam and the standard verb piję?

Piję simply means "I drink" or "I am drinking." Popijam (from the verb popijać) implies drinking slowly, casually, or in small amounts over a period of time, which is why it translates perfectly to "I sip" or "I am sipping."

Why does the inanimate noun kieliszek (glass) take the ending -a in the genitive (z kieliszka), which is usually for animate masculine nouns?