"Sometimes we are right and sometimes we are wrong."
Translation:Foje ni pravas kaj foje ni malpravas.
"Foje" is officially ambiguous. Sometimes it means "unufoje". Sometimes it means "kelkfoje." Best to avoid it.
why is "ne pravas" not accepted? shouldn't it mean basically the same as "malpravas" (since "not right" is the same as "wrong")?
I'm actually a little torn on how I think that should be handled. On one hand, you're correct that the meaning of the sentence is more or less the same, but on the other hand, perhaps Duolingo should focus on ensuring you know how to translate in ways that are essentially word for word when possible? ("Ni ne pravas" for "We are not right" and "Ni malpravas" for "We are wrong")
why is it "foje" and not "kelkfoje"? what even is the difference between the two?
Kelkfoje is more explicit. Foje depends on context as to whether it means "once" or "at times."
I might be wrong here, and this is only my interpretation from looking at the definitions of each word, but ĝusta seems to imply being more factually correct, as in declaring that sodium ignites and dissolves in water. That is a fact and is correct (seriously, look it up on YouTube!). It also means answering a direct question correctly, or factually (as in a teacher asking if sodium ignites in water, and a student responding with yes).
Prava has to do with opinions more so, as in having an opinion that is accepted by most as correct, or having a certain stance in an argument that some other outside person (or later your opposition) considers to be correct.
Prava also implies moral correctnessh; an idea that is a fact, like the sentence "Hitler persecuted Jews," might be ĝusta, but it is not prava because it is morally wrong (at least in most people's eyes, morals being subjective and all).
In the case of this sentence, they seem to be saying that they are sometimes morally right or have correct opinions (and sometimes not), not that they sometimes answer questions factually and sometimes not.
I also think that if you say something that is "gxusta" then you are "prava."
I don't think that's quite right? my understanding is more that ĝusta means that something is right, but prava means that something (or more often, someone) has expressed something that is right. so like salivanto said, if you've said something that's ĝusta then you're prava