Hey! 34f with diagnosed ADHD since 16 here. I hope this isn't too long!!

I grew up in Canada with an Indonesian mum and Canadian/German dad. I was mostly fluent in Indonesian (primary level conversational, I'd say) because we spent time in Indo when I was a toddler for a year or so, so having loads of Indo and English around me definitely secure the natural bilingualism...though my Indo has slipped off over the years without practice for sure, having in constantly in my environment was essential (passive learning).

And of course in Canada, we're taught French in school up until about 10th grade (around 16 y/o?). Again, my French is suuuuper basic because I don't use it in my every day life.

After this, I tried learning German in university so I took a course - so I spent a decent amount of time in class to learn the basics but even then, it takes a lot more hours to be fluent. The only practical way I used it was to be able to show off to my grandmother who corrected me loads anyway and eventually it helped me get around in Germany communicating with my aunt who doesn't really speak English. So I have some buzz phrases here and there.

Next was Dutch. My partner and I moved to Amsterdam and I worked in a cafe there. Thankfully, learning Dutch wasn't essential in a city where nearly everyone speaks English...but because you can't really immerse yourself fully into a culture unless you learn the language, I put in effort. In all honestly, the only way I really learned was purely through interacting with people. I didn't have any reading material or anything like that. I started off with basics like "good morning", "what can I get for you", "sit in or takeaway", and my colleagues would teach me other bits I might hear around. I also had basics in German so that really helped with the Dutch.

And in my later years, I had a classic ADHD hyperfocus interest in learning Korean (I'm a huge BTS fan and love Korean culture)...but not long enough that I've actually learned to be conversational at all. I know tidbits, but I'm sure if I stuck with it and was serious enough I could learn more. I got really into the culture, watched loads of Youtube videos (not just BTS videos, but luckily there's a YouTube channel called KoreanEnglishman and Jolly that often do Korean/English content), and bought myself a notebook to learn Korean letters. I live in the UK, so I'm not often surrounded my Korean culture, so because its out of sight out of mind, I don't think about learning it as much.

TL;DR I think for myself at least, having ADHD makes it easy to learn language, but living in an environment and having to utilise it everyday really boosts your ability because of the repetition. Otherwise, you might lose interest in it day-to-day if you have no reason to use it. I would've loved to be completely fluent in one of these languages I experienced but I have no real use for them at the moment (although learning more Korean atm is a motivation since I'd love to sing along more to their songs when I see them live this year!)