Get into an environment where you can't speak your native language. I used to tour with bands as an sound engineer and being forced to speak English instead of

Get into an environment where you can't speak your native language. I used to tour with bands as an sound engineer and being forced to speak English instead of Dutch did a lot, fast. The only downside is that I incorporate too much Scottish slang nowadays... I still review all my conversations for a minute to find out if I did formulate the way I would have done in my native language, and reformulate as a exercise for the next time. It's pretty Lean, but you must keep it going.