I agree with Massimiliano. Constant practice is what you need. I can help you from time to time of you need.

There's no a right answer to your question; you should study grammar, and listen to as most podcasts and audio as you can, maybe, that's my advice. Constant practice!

دراسة قواعد اللغة الانجليزية جيدا مع حفظ الكثير من المفردات