I just want to contribue my two cents on the topic: How to learn English.
Personally, I have found two very succesful techniques for learning English.
One of these techniques is writing. If one writes analytical papers his English is likely to improve. By bringing this fact out I want to point out that there is a difference between a personal journal and academic papers. The value of academic papers lies in that we try to use what we have heard and present it to others. This is an objective approach. The perils of personal writting lie in the fact that we only write for ourselves. Therefore it is likely that we may mix English with our native language and ultimately our thoughts may become incomprehensible for others.
When we write for others we are exposed to what I call subjective learning. In other words we learn English through our own experience. In contrast to reading while we write we try to use what we have heard. I use the term heard broadly. It includes various things: grammar, words, language rules. When we write we try to use all these tools and create our own sentences. This approach gives us a personal experience of the language and is most useful.
In fact, I consider it to be the most effective approach to learning.
There is another approach to learning that I have found useful. I am actually practicing it now. We learn when we teach others. We learn when we show somebody what they have done wrong. To put it differently, while we are helping others we are helping ourselves.
Some may find it perplexing however during my job as a teacher I have learned a lot. I may even say that I have learned more than I have taught.
The value of this approach lies in the fact that when we teach we bring things from our subconscious mind to our conscious mind and can have a second look at our ideas. Exposing our ideas to our conscious mind will allow us to look at them more critically or from a different perspective.
One of my Economics teachers had a fact sheet which said that 99% of what we learn is through teaching others.
It is very helpful and my own experience has proved its worth.
These are my 2 cents.