Random Question for You!

For those of you who have already traveled abroad before:

Name a country you’ve been to.
Name one overlooked word that you think travelers absolutely must know in the native language.
Why that word?

My Example:

South Korea —

While the most important word ever is “I’m Sorry” (Miahne), a lot of people already know that one. What they don’t mention is “Yok” (long o). That’s “subway station” in Korean and is used for everything in regards to directions. Even the locals give directions in terms of which exit of the subway you should orient yourself to. Lots of times you’ll be dropped off by taxis at the closest Yok to your destination. It’s the one word you definitely need to know if you’re going to be in Korea, even for a day. But it’s rarely on the ‘most translated words’ lists.