what's the shortest way to be fluent in English or any other language?
Fortunately, there isn't any short way of doing things here on earth. Just imagine doctors finding a short cut of becoming a professional, I bet we don't want to see those doctors in hospitals, short cut engineers making durable building, dosen't it sounds funny;))) so buddy if you want to master English, pull up your socks and start reading a lot. Best of luck:)))
It depends on your practice, effort and dedication...
I think listening is very important for sure, but being sorrounded by a situation where you have to speak or speak is the best way,I mean living in a country where the other language is spoken everyday , and you can listen to it all the time, but if this is not your situation, read and listen is good.
sorry there were some problems here so i had to put my comment again for your convenience.
good luck