https://www.mangolanguages.com/libra...#/search/32162
French is easy if you can get the pronunciation and practice it quite a bit. I found Spanish easier though even though still cannot pronounce some of the words. German is quite more difficult as is Dutch. Chinese and Japanese I found quite difficult along with Russian.
Italian is fairly easy with a background in Latin.
I took a bunch of languages so I would be a better cataloger of foreign language materials in libraries while at the University of Minnesota Law Library but had taken French, German and Spanish before starting law school while getting my dual BAs and MA.
I have not mastered any foreign language though as it seems you have to use it fairly regularly to learn it quite well.