Questions & Answers about Zimą noszę ciepły sweter.
Why is Zimą used here instead of just zima?
Zimą is the instrumental case of zima (winter). In Polish, seasons and times of day often take the instrumental case to mean "in" or "during" that time. So, while zima means "winter", zimą means "in winter".
Doesn't the verb nosić (noszę) mean "to carry"? Why does it mean "I wear" here?
The verb nosić means both "to carry" and "to wear". In Polish, wearing clothes is expressed with the exact same verb as carrying an object around on a regular basis.
ciepły sweter is the direct object of the sentence. Why don't its endings change?
Because sweter is a masculine inanimate noun (a non-living object). For masculine inanimate nouns, the accusative case (which we use for direct objects) looks exactly the same as the basic dictionary form. Therefore, ciepły sweter doesn't get any special endings here.
I sometimes see the word swetra. Is the basic word sweter or swetr?
The correct basic word is sweter. However, that second "e" is a "fleeting e" that drops out when you add endings for other cases. That's why you wear ciepły sweter (accusative) but you might not have ciepłego swetra (genitive).