Hello guy! This is a psychological question, I guess. Once you have started using a language from day to day, you start thinking in that language very often, without having to translate your thoughts into that lanugage. One way to reckon that you think in a language is to see a dream where you are fluently speaking in that language while talking. I was in India, I was fluent in Hindi, was in Russia so was I fluent in Russian, and am in Amerika and fluent in English. I used to speak French when I lived at Pashupati in Nepal, but now I can comprehend it (Pous Je?) and speak it but am sure French will not be able to make it out. I need to a long vacation in Paris and some interaction with a slim parisienne for a while before I speak it to their liking! The result is I've an accent in all languages, including my mother tongues (according to my wife)...