First of all, if you want to learn English very well, you should read books, newspapers, and articles everywhere and every time, because you can learn English grammar in this way.
Another way of learn English is to listen A LOT you can listen to music, audio books, and can watch movie and TV series. Listening is important because it can improve your listening ability.
Next, writing is the other way of learning English.you should write e-mails and letters in English. I think writing is the most important step for learning English because you never learn English when you don’t write anything.
As a result, if you want to learn English very well; you should follow these three steps.
Good Luck ! :)