I did learn Japanese for a while but lost my motivation when it came time to learn Kanji. Can still read hiragana. I can read and write Hindi and speak it a little but lack vocabulary and confidence for an actual conversation.

Fluently speak only German and English. I used to be conversational in French and Spanish but decades of neglecting that leaves me with little more than the ability to recognize words.

Definitely can't loose indigenous languages like maori, it's a massive part of what has kept the culture alive after it just about being stamped out.

corrupt what languages do you speak?

I found Latin to be very simple to pick up, but it’s hard to be conversational now since it’s a dead language and there’s no one to speak it with. My vote would likely be Latin though, or possibly Greek

At any rate, learning languages is super fun and empowering. I can only recommend it to anyone. Even if you never get to a fluent level. You'll learn a lot more about your own language too, when understanding another's structure

I find the first one more intriguing on an academic level. Which would be the easiest to learn and become fluent in on a global scale, no matter what your native language is.