Good to see so many multilingual people on here.
English is my primary language. Tamil was my mother tongue but I haven't spoken it regularly since I was 10 so it sucks now, though a stay in Chennai or Sri Lanka will have me back up to speed. I also speak fluent Hindi, Marathi & Gujarati. And very bad French that I learnt in school and some tutorials online...
I'm going to dedicate a year each to learning Mandarin, Spanish and Arabic. They have the most speakers worldwide after English. And finally Japanese, because it's just freaking cool...