The beauty of language is that our understanding of it is always developing. We use words to express ideas, and language provides an infinite platform on which to share those ideas. Keep at it: read, speak, write, think, watch, hear the language and let the words come to you. There's never a point when you'll have conquered the language. As the saying goes, "It's about the journey, not the destination."

As with any language, it depends on how much you work on it. If you are diligent and practice it every day, you will learn it much sooner than someone who only practices once a week. The time it takes to learn a language is different for each an every person and, therefore, is impossible to tell how long it will take you. Also, to correct your title question: We say "in English," not "on English."

There´s no specific time ... It depends on you and hw much you practice. The more you practice the better you will be!