how to be a successful language learner?

There are so many books available to learn any language. Read them and try to converse in that language. Whether you are speaking correctly or not, don't bother. just speak on and in this way, you can correct yourself and one day, you will become an expert in those languages

I believe it has to start with interest.you have to be interested with the language/s you'd like to learn.learning new languages takes some time and patience.if you're really not into it, you might get bored and decide to quit it.

I agree on the actively and purposely part but, if you don't have anyone to practice your new language with, I think it would be a bit difficult as you do need to apply what you have learned after all. I learned elementary spanish before and my teacher said that I was good at it too but, after not being able to apply what I learned, I only know a few words and phrases. I believe constant practice helps so independent study, though possible, is rather difficult..

I think you have to learn actively. In high school, I had taken 3 semesters of German when I won a scholarship to live in Germany for one year. When I got to Germany, it surprised me how little I knew. In order to learn the language, you have to get out there with people who speak it and learn it. Textbooks can teach you the basics but its that people and culture that will drive the language home. I learned more of the language in one week than I did in a year and a half. And you dont need to go to the country to learn the language. Start reading newspapers, find online radio stations, chat rooms, etc. If you become proactive about the language, I think it is a lot easier to pick it up.