Ask HN: To those who became fluent in a second language, what did you do?
There is no substitute for living in the country and avoiding your native speakers like the plague.  Immerse yourself completely (take a few language courses, move in with locals, make an effort to avoid English speakers at all costs).  Give yourself little challenges:  Groceries, info about the train, museum, read a leaflet, book an activity, ask questions at a restaurant (even if you don't quite get the answer)...People will want to practice their English with you.  Be stubborn.  Reply in the foreign language and let them talk in English.For the first 2 months you will feel incredibly tired at the end of each day.  Your brain will fight to stay afloat but that stress will make it learn so much faster.  Around the 3rd month something clicks and you start to talk more and more. After that, the progress becomes almost automatic.  Try to study something, or work or be part of some local group.One key element is to avoid perfection.  Understand that you will never speak perfect grammar for years (just like kids make silly mistakes, you will too).  Embrace it, have fun, make mistakes ... enjoy the trial and error discovery and the challenge of communicating ideas with rudimentary tools.  Be patient.  You will get frustrated because your brain has complex and nuanced ideas but your language is as basic as "me not good" or "me good".  You will learn that body language and tone already communicate more than you can tell with your basic language.After a year you'll be pretty fluent (You'll be able to hold a conversation with anybody, on any topic, but still peppered with clarifications and questions).  Mastering a new language would still take many years (with lots of reading, writing, talking, etc).(source:  I speak French and Spanish as native languages, English as third language and German as 4th which I learnt as an adult living in Germany for a year)