What language study?
I have clear which languages do I wanna learn, but I just want people to say languages and say why should I learn this language.
THE LANGUAGE DOES NOT NEED TO BE ON DUOLINGO
Dutch! It's not one of the big languages like Spanish, German, and French, so if you learn it you'll know it's because you want to and not because someone said you should because of the number of speakers.
While it's only spoken in a few countries, once you learn it you'll be able to understand most of Afrikaans already! So you're getting two neat languages for the price of one! Plus, if you want to learn German, learning Dutch first makes it a lot easier.
Also, Dutch is just fun! So you should at least try it out to see if you like it. :)