Think about how much time you spend a day speaking even your own language in your daily life. Do you think it's 16 hours in a day? 400 hours of practice is a p

Think about how much time you spend a day speaking even your own language in your daily life. Do you think it's 16 hours in a day? 400 hours of practice is a pretty good rule of thumb I think, but that's deliberate practice, not just physically being awake in a country that speaks the language. You need to be engaging in conversation and actively processing things for those 400 hours. Plus it has to be at a practical level. Watching TV in Japanese when you don't know any Japanese doesn't make you much better at the language - your brain isn't really processing anything. Or to make a music metaphor, you can't really just play with a violin for hundreds of hours and be good. You need a tutor, someone to challenge you at your level and help you make small steps so you slowly get better. Anders Ericsson has done some fascinating research on excellence and the important difference between doing something and deliberate practice at it. Also, don't mistake being in a country with language immersion. When I was in Paris and knew some French, I would maybe be able to do a few hours a day at best, if I was really trying to engage. Even in English in America, I probably only really talk or engage in conversation for a few hours a day on average. I was in Germany last year for a few weeks when I was around an A1 level and I barely progressed, because the immersion is very surface-level at that stage. You have encounters but it's not really practice - most interactions are too high-level and don't help you because you can't process them.