US money is perfectly acceptable at HK and most of

US money is perfectly acceptable at HK and most of the places in TJ as a matter of fact. Make sure you bring some small bills though, because they may not always be able to break a big bill. I’ve heard there may be some advantage to getting more for less if you negotiate in Pesos, I don’t know if it’s worth it or not, considering the hassle of exchanging the money, and then selling any Pesos back that you didn’t use.
As far as language goes, speaking Spanish is a plus, but by no means a requirement. Even before google translate I was able to communicate enough to get by.