Thanks for this, I found it really interesting. I just went on Wiktionary and found nieść, and one of the definitions listed is wear, just like with nosić: https://en.wiktionary.org/wiki/nie%C5%9B%C4%87
You say that Polish doesn't have a "wear currently" verb, so when does the wear meaning of nieść apply? Does it get used for wore, and it's just not idiomatic Polish to use this in the present tense, or is there a special case where it means wear?
The comment levels are a nightmare indeed :/ Woah, that seems the most serious mistake I've seen on Wiktionary so far. No, "nieść" does not translate to "to wear" (nor to "to be wearing"). "nosić" indeed has both meanings, but it's not true for "nieść". Unless it's some weird regionalism I am not aware of, no one would say "Niosę kurtkę" to mean anything else than "I am carrying a jacket".
The idea of wearing something currently, as immery stated, is conveyed by using "mieć na sobie" or "być ubranym w".
None of those has been introduced in the current version of the course, causing problems regarding the accepted answers. Currently some sentences still accept "to be wearing" despite the fact that it's not really a translation of "nosić", which should be only used in Present Simple.
P.S. I removed "to wear" from that Wiktionary entry, I hope no one will try to re-add it.
For some reason I can't reply to your other message, but I am aware nosić is wear, which I mentioned in the original message. What I found was that nieść has a given definition of wear as well, and I was asking when that could possibly be used. Given that nieść is a concrete verb, it should apply to the situation where I am wearing something now, like it does in the case of carrying, but immery claims that neither noszę or niosę are used for "I am wearing".
The whole position was interesting to me because I was under the impression that noszę was used for, "I am wearing", but perhaps I was wrong in that assumption, and it only means I wear x habitually.
This limit on the number of comment levels is annoying. Anyway, I believe you regarding the Russian, and this hasn't been taught on the Duolingo course, but I've now found three separate sources listing nieść as meaning both carry and wear, while nosić means wear, carry, and bear (as in a title). Could be a mistake with the error being proliferating by the various resources citing each other, but I wanted to get some additional opinions, because the various sources are not adding up here.
EDIT: Looks like the wiktionary definition has been the same for 8 years and has survived more than a twenty edits, so I'm not sure that's a mistake.