Well... I learnt English at school with books, videos and teachers. But, the big challenge for me was to learn portuguese being an adult. My husband and I had to move to Rio de Janeiro in 2012. I'd never been interested about learning Portuguese before... but I had to: we were living and working there. Portuguese seems to be easy for a Spanish speaker, but that's not so true. (Advantage: Portuguese is very similar to Spanish. Disadvantage: Portuguese is very similar to Spanish.) At first, people tried to be friendly with me because they thought they could learn Spanish just by talking to me. But, as soon as they realized that that was imposible, I lost many friends. Nobody wanted to practice with me. So, I bought a Grammar book, a good dictionary and I started to watch TV. I also tried to find a Portuguese course, but I had no luck. I hightly recommend studying grammar when you want to learn a new language. That's the basis. Once I knew the grammar and the theory, I contacted an Spanish teacher in Rio de Janeiro and asked him to help me with my oral Poruguese. I learnt Portuguese in 3 months and then I took the CELPE-BRAS exam. I got an advanced certification. That's my experience.