what does 'exfil' means? what does 'exfil' means?

I am bace 7 months ago i register my ID on italki.com with a wish that i can talk with english speaker. i'v been asked for learning english since i was a primary student, i'm 25 now, you see, a decade for learning a lunguage. but actually i think my level is no better than a 10 years old english speaker. it's much diffrent now, no one push me to learn english any more as a sbuject which is at least in my country. now it's me who want to speak english from my own wish, a wish that a curiosity to diffrent culture, to broaden my horizon, or simply for english shows, movies, books. I'm not a clumsy learner, it's the motivation and the wrong way result in my low level english after a long studying. lunguage is just a tool for me, if we both get what we express each other, that's will be ok. further that, if i can speak more fluent or have a native accent by a period of time communication, that will be marvelous for me. As the begining, this ID has been exist 7 months, and i'm not on line for 6 months. even back then, i find so many chinese speakers're seeking for english partners, you know, it's not easy to establish a steady partnership, at the first month even only few couple guys want to chat with me, you know, just few simple words. i almost give up on italk. but i'm back now. Well, what i want to say is, i am seeking for native english speakers sincerely. and i must declare firstly that i can just speak mandarin, but i'm well educated, i believe that i can help you to improve your level if you want to acquire mandarin. i expect for a 50/50 exchange, any topic, any chat is ok, skype or not is ok, i can compromise with your local time as much as possible, just hope for developing into a steady partnership, even a friendship. not only for lunguage ablity but also for two diffrent world experience exchange.