You don't understood. Most of you teachers here, right? And I'm pupil here with great experience. I'll try to explain. When you live in a country where no one speak in foreign language, in order to effectively study and progress in it, you must place yourself in such enviroment where you'll be surrounded with language speakers. You must know that same word you can say in many ways. When you familiar with all this ways of pronunciation of the word, you can easily perceive everyone with all ways and manners of speech. For instance: the same word a can easily perceive from one person and ever not know about what talk another. Only way to know it is to read it on lyrics or subtitles (movie). All this types of pronunciation information of one word saving in our mind with association to the one. My be you think that one type associatied is enogh? It will result in pecieiving. That's why I try to create enviroment with speakers with all types of pronunciation. My be "50 cent" is not a best choice, but I not found anything else on that kind of pronunciation. He says many normal english words on his manner of pronunciation. I think, its useful for me. And by the way of listening I studing meanings of what I listening. Without it there is no thing to what attach version of pronunciation in the mind.
And after that only I filled a progress in perceiving and memorizing of words and expressions. You saying grammar? Look, how child progressing in acqiring language skills. First he styding words and sayings and learn to perceive people without that boring rules, that can easily cause aversion of some kind of pupils, I think. Only when he acqired that skills he began to study rools in a school. In that acpect I'm a child because, I'm growth in enviroment where I havent that experience which have American or UK people from childhood.