Some people think that the best way to learn a language is "learning by doing" rather than learning through books and teachers. To what extent do you agree or disagree with this opinion?

Some people might agree that the best lesson to have is by being taught with a teacher. However, I disagree with that position, especially when it comes to learn a new language. Language is an important bridge to connect between two people’s feeling, thus, practice is the best way to actually master a new language. […]