Discounting native tongue of english which is obviously the easiest for me... French would be the easiest I think, I studied french from 5 years old until 16. I can get along passably in french and I can generally understand most things like French videos/music/books but occasionally more complex vocabulary trips me up. Japanese would be the next easiest, once I'd learned the letters (Hiragana, Katakana and the basic Kanji) the structure of the language is very simple and not too ambiguous, it's also pretty formal so there isn't an ungodly amount of colloquialisms to learn like with french or english. It was a tricky few years to really get on top of the structuring and the core of the language/grammar but now it's quite easy and simple to learn new words through songs/films/anime/books. Just Dat Kanji doe... still -blam!-s me up. Spanish gets the vote for hardest because I was having french and spanish lessons simultaneously and if you've ever done that... it's very confusing... I mixed up so much of both of them at one point that I just wrote off spanish all together. However, if I hadn't been learning French and Spanish at the same time - Japanese would take the winner because of that bastarding Kanji. Did I mention I hate Kanji? I think I did...

Easiest Latin Hardest Arabic or mandarin

I haven't started learning german, but I can comprehend quite a lot of text in german, so I guess that the most difficult one is spanish? Spanish isn't really that difficult, but I'm 15, so it's probably that reason. When you're younger you learn quicker. I learned english from watching movies and playing vidya, and I learned swedish by hanging out with my brother.

Tfw only know two languages.