I moved to Germany knowing NO German (I was already fluent in French, though). I could hold a functional conversation after 4 months. By the end of the 2nd year, I was fluent. By the end of the 3rd year, I could speak rather creatively/poetically -- not just functionally.
The caveats that Soj mentions are so true, though. Although I believe it's the second year in country that you want to kill everyone you meet. First year, everything's kinda new and exciting. By the second year, all you want is a burrito/slice/collards and you keep wishing for the relative efficiency of the Dept of Motor Vehicles. Being away from friends and especially family is really hard, though.
By the third year -- you've made some long-term friends, you've started forgetting the English words for things ("fork" and "knife" always flummoxed me when I went back to visit the 'rents), and you start to get nervous if you're back in the States for too long.
Personally, I'd dig on moving to Eastern Europe at some point -- but right now the goal is either Shanghai, Tokyo, Hong Kong or Seoul. Because it's time to learn another language! Just another science harpy.
as a tip -- if you managed to learn Esperanto, you've already mastered the hard part -- training your brain to pick out linguistic patterns. It really is a process, like writing code.
It's the compiling that's a bitch. ;-) Just another science harpy.
