[Dr Mantis Toboggan]

Mandarin. The purpose of the school is to teach military personnel critical languages for national security (hence the most common languages I listed a few posts back), I can't say they've never taught Cantonese there (maybe back in the 50s/60s?) but they don't now.

As for classroom vs live learning...speaking with strangers is the best way to develop your skills but it's only a major difference if you're in a full immersion environment, outside of Spanish you aren't going to really find that in the US. You can get some practice with the Asian languages though both in Monterey itself and especially if you go up to San Francisco or San Jose. Some friends and I also met a bunch of mainland Chinese students from MIIS--a small university in Monterey aligned with Middlebury College that focuses on international studies and has foreign students from all over--I actually went out on a date with one but then got paranoid about getting spied on by MSS and ghosted her (one guy actually married one, but he was kind of "special"). It'd probably be easy enough to get outside practice in a lot of the other languages like Farsi and Russian too.