Thanks for the A2A first.(Or do we call it the BuA at Quora DE?)
You learn English the fastest using the same method as for any language: immersion.
Research has shown that you can achieve true bilinguality, no matter what age and no matter how language-savvy you are, if you use the second language permanently at least 30% of the time in everyday life.
It may seem weird at first glance, but it’s a matter of whether you make mistakes.The main thing is to try to invest as much time as possible, to use the language — to speak, to hear, to read and to think(perhaps most importantly).
30% can be easily created in everyday life.It’s just a matter of wanting. Above all, it is particularly easy with English. You read daily news in English (TheGuardian, New York Times, Times of India, The Economist, CNN, etc.), you watch TV in English (by satellite, digital cable TV, Internet), you speak English with others who want to learn English or already to be able to.You write a diary in English, even the shopping list. You can listen to English radio stations such as NPR Berlin[1 or BBC World Service[2 or the countless Internet radio stations.
DVDs are almost always multilingual these days, and English is almost always there.Netflix and Amazon Prime also offer movies and series in English, with and without subtitles. Initially you can watch movies in English with German subtitles, then English with English subtitles, then without subtitles.
It can be especially helpful at the beginning, e.g. if you read the English version of Deutsche Welle[3 or Spiegel Online[4 and watch videos there.You will probably already get to know the topic — and learn vocabulary faster, because you already know the content in advance.
Find partners with whom you speak only English — whether native speakers or not, it doesn’t matter as long as you’re also involved in English-language media.
Again, it’s completely whimpered if you make mistakes. Your goal should not be to speak error-free.Rather, your goal should be to speak fluently and safely and to understand your counterpart.Everybody makes mistakes, even native speakers. If it happens, shit happens.Laugh at it and learn from it.
I still make mistakes in German after 24 years of practice, but nevertheless I am considered to be safe to negotiate.Everyone in English manages this with diligence, patience and commitment.
Good luck and have fun!