How can I know, when to use 'die', when 'der' and when 'das' befor words in German

Sitting home It is already four weeks, since I broke my leg while skiing in the mountains. So I have a lot of time to learn a language. Currently I'm using Rosetta Stone software to learn German. It's going pretty easy. Has anybody tried it? The weather out there is very cool. Snow is about half a meter thick. But I have to sit home, because I can't walk. And there ist one month still to go...

why do american military say "roger that" when they confirm command? What is historical background of that phrase?

Who is interested in learning English via listening audiobooks? That is very effective (my opinion)

Do you listen audiobooks in language that you learn? If yes, is it useful for you?

Why do you learn foreign language?

How do you think, how old is the Earth?

What is the first thing you think about Ukraine? First what comes in mind.