I'm generally curious about how the brain manages multiple languages and dialects, and in particular, how it manages to switch rapidly between them in real-time conversations. I'm sure most people have had the problem of entering a new language environment (i.e., comprehending what others are saying and formulating a response) but when they speak, the language of the previous environment comes out. For example, suppose that you just got off the phone with your mother from Italy, and you were both speaking Italian. Then your wife comes home, with whom you speak German, and you know you want to greet her, but you continue in Italian instead of switching "cleanly" to German.
Why does this happen? And is there a way to improve the brain's ability to switch?