I think knowing English grammar helps me with my Portuguese... I can compare and contrast the use of tenses, for example. The grammar may be very different but it makes me more confident. But this is because I need structure.. I am only happy when I have structure in my learning! Other people might be more flexible and be able to ignore the grammar books and just learn by ear. They listen, they repeat, they absorb. LUCKY PEOPLE! This is why it's important to use all sorts of strategies when learning, or teaching. You never know what might actually get the language into your head, and back out again as coherent speech! Quizzes, songs, games, grammar, spelling tests, dictation, photos, YouTube, and all sorts of things! Try them all! Songs can be great for grammar (or spotting the mistakes!). But I agree with you Frederico ... grammar helps ME learn too. It's my way. Not everybody's way, but my way.