Antonio, ten out of ten for enthusiasm and determination. First, you will never be a native speaker, just as I could never be a native speaker of your language. However, what you can be is BETTER than many native speakers. There's an exam called Proficiency, which is above advanced. Many native speakers of English would not pass this exam. Partly because they may not be good at exams, of course, but also because their spelling and grammar are flawed. I think that 'being a native speaker' is a little overvalued. Some native speakers of English have few skills in the language, cannot write coherently, mangle the verbs, fail to enunciate clearly... and cannot spell. Yes, they can understand every word of The Simpsons, and they can chat happily with their mates down the pub.... but they don't speak English 'correctly' ... and would struggle passing exams in English. The same is true of people in your country. Some speak the language beautifully, others grunt and misuse it. I'm not really making value judgements here (well, perhaps I am!) .. I love regional accents... and weird idioms and slang... but not if it obliterates clarity and understanding. I'll add a link to an interesting article or two at the end. Have a read. And do read good quality newspapers to become familiar with good standard English. Furthermore, I suggest you acquire a proficiency textbook off Amazon. There are self-study courses, with audio. Make sure it is proficiency level. You will find the work challenging! Remember, even a native speaker would find a proficiency textbook challenging... and some of the less educated native speakers might give up! In summary, aim to be proficient rather than to be native. Native does not equal good. I have friends who make me wince when they talk! http://www.dailymail.co.uk/debate/article-2088949/Rise-elocution-lessons-Lets-confuse-means-speak-Proper-English.html

Even native speakers need their writing 'proof-read' to check for mistakes. Really all you can do is get someone to check... also keep studying as even native speakers can improve!