dano2

I'd recommend Memrise. I haven't used Duolingo much, but in Memrise, users can submit text/images that can help you remember what you're learning, in addition to scoreboards. I used it to learn some Russian, Swedish, and other languages. I think it's genius.

Apparently Esperanto is one of the easiest, if not the easiest, languages in the world to learn. It was made by L. L. Zamenhof, and up two million people worldwide speak it. Its vocabulary is mainly from Romance languages, with a Slavic sound inventory.