How can children learn a foreign language within half a year? And why does a regular person spend years of difficult studies on the same task?
We all speak in our native language, perfectly. However, not all of us have received high grades during our mother tongue classes, in school. A language is an audio-visual dynamic environment of images. You can either imagine it as a system of rules and regulations, or you can jump into it as if you are entering a river. To learn it, is figuratively speaking, to learn how to swim. Once you have achieved the basics, you can learn the technical theory, and how to use it correctly.