Difference between das, diese, and jene?
I had to translate "Those are cups" which I thought would be "Diese sind Tassen." It told me I was wrong and it should be "Jene sind Tassen." I was under the impression jene was only used for comparison in 'this or that' situations. And if that wasn't confusing enough, two questions later it asks me to translate "Das sind Tassen." and it tells me that is also "Those are cups."
Okay, so how do I know when to use das, diese, or jene when referring to things that are this or that or those etc.?
That can be very confusing. First of all, "jenes/jener/jene" is almost never used in everyday speech. It's literary in style, I wouldn't worry about learning it.
Instead, you make a distinction only between "das" and "dies/diese/dieser". (My, German seems to be getting more complicated as I type.) When you say "Das sind Tassen", "das" is a demonstrative pronoun that isn't bent, different from English (where you say "those" to be in agreement with "are"). Note that in this case, "das" doesn't act as the neuter article.
So "those are cups" would be "das sind Tassen" or "die (da drüben) sind Tassen" (those over there are cups.)
Diese Tasse: This cup. Die Tasse da (jene Tasse): That cup.
Das ist eine Tasse: That is a cup. Das sind Tassen: Those are cups.
Dies sind Tassen (rare): These are cups. ("Das hier sind Tassen" would be a more common alternative.)
I hope this helps at least somewhat!