If you mean "learn" like most kids in American high schools learn another language from a book in order to be "conversational", then I'd say no, machines are (o

If you mean "learn" like most kids in American high schools learn another language from a book in order to be "conversational", then I'd say no, machines are (or will soon be) good enough to provide this level of translation. If you mean learn as in immerse yourself in another culture long enough to begin generating the spoke language from "first principles" as it were (ie: enculturation), then I highly recommend. It changes your perspective in a way that can't be easily communicated to someone whose never experienced it. It will allow you to create translations that machines will be completely incapable of in the near future and probably even the far future. In practice, it reduces to the difference between translating what was said and what was meant.