"I do not know anything about this."
Translation:Nic o tym nie wiem.
Aa... I get it now :)
So, you wrote:
"Nic wiem nie o tym."
But this is actually an incorrect sentence, since nic and nie are swapped. It would have been correct if you had written:
"Nie wiem nic o tym."
Unfortunately, the grading algorithm counted this as two typos (which it shouldn't have), but unfortunately we have no power over how grading works. And it seems that the developers currently aren't doing much about this problem.
Now, why was "Nic" capitalised: The proposed solution had an alternative word order, namely:
"Nic o tym nie wiem."
As you can see, it's important to not split the negation and the verb.
I'd usually say that znać always requires a noun or a personal pronoun as a direct object, so if you have a preposition, you need the verb wiedzieć.
However, when looking this up in the corpus, I've come across a few sentences like these:
Ale znamy o nich jedynie przepiękne legendy.
But all we know about them are beautiful legends.
Here it sort of works, because the direct object is 'legendy', while 'o nich' is just an additional piece of information. You could omit 'o nich' and the sentence would still make sense.
Now, you might ask, couldn't we omit 'o tym' here, too? When a direct object of znać is neither a noun, nor a personal pronoun, znać gets a specific meaning: "to be familiar with". Hence, the sentence: "Znam to." will mean: "I'm familiar with this." So, I imagine that "Nie znam nic" would mean "I am not familiar with anything", although I'm not entirely sure, because can't really recall ever hearing it.
All of this does not affect the reflexive verb znać się (to be well versed, to know one's way around) which is usually followed by the preposition na. It also doesn't affect the collocation dać znać (to let someone know) which can be followed by the preposition o.
You just don't use the verb "znać" that way. Maybe that would help a bit: https://forum.duolingo.com/comment/25535826
znać (meaning "to know") takes the following forms:
- znać + Accusative = to know something/somebody
- znać + jako + Accusative = to know something/somebody as something/somebody
- znać + od + Genitive = to know something/somebody since...
- znać + z + Genitive = to know something/somebody from (eg. from a book)
But znać does not take the preposition "o".
wiedzieć takes the following:
- wiedzieć + o + Locative = to know about something/somebody
- wiedzieć + od + Genitive = to know from somebody (eg. from a friend)
- wiedzieć + z + Genitive = to know from something (eg. from ones' experience)