My native language is Dutch, Nederlands dus
and my english is good, has to be since my Master studies in Medical Biology is in English. My classes, tests, books, everything is in english. Also, I read my books (for fun) mostly in english, somehow it seems that most books I'm interested in are originally written in english.
I did have a boyfriend in england for a while.. that's very good for learning to speak another language. First time there was weird, but after a while you don't have to think about turning your own words into another language. After a week or so you think in english.
I can understand german pretty well, but speaking it, hell no. French.. had that for six years in highschool and now I don't speak more than a few words anymore.