It is not easy to learn a second foreign language that is not our mother tongue. Because, language is one of the customs. So, it is difficult to break the frame of familiar customs.
When I learn a foreign language, especially English, I learned English during seven years, now, It is so difficult to speak and write in English. However I think that is not only caused by the frame of familiar custom.
When I learned English, during the six years, (middle school, high school) I was trained to accept knowledge by a hearing test or reading over and over. But I wasn't trained to have conversation with somebody