The US military has a school that teaches people languages very quickly: https://www.dliflc.edu/ https://www.dliflc.edu/ . It's very interesting how they teach,

The US military has a school that teaches people languages very quickly: https://www.dliflc.edu/ https://www.dliflc.edu/ . It's very interesting how they teach, in that there are multiple methods, categories, and amounts of training depending on both the language itself and what it's going to be used for. They have an impressive track record and work very fast.