Hi, I do believe that, everybody has to rely on his/her own efforts to fulfill his/her dream of being a bilingual, trilingual, or even multilingual speaker. & The best method is to get hold of some authoritative and reliable textbooks, dictionaries, & grammar books. It would be of little help to learn a foreign language only by practising oral English or slang words, of course, even if colloquial English is very useful, the basic skill for foreign languages is quite necessary, & I'm sure that you'll benefit from your steady level gradually.

It depends on your self motivation, you can do it for free here at Italki, or pay to go to a course, or just borrow books from the library. How much time have you got to spare?

i trust if you really want to learn, you will choose the best way for yourself, so do your best to try.

Go to the country which the language is you want to learn ...hehe ,stay in here for several month,you will be a native speaker,of course you also will be a begger if you didn't open your mouth,,,right??