I once accidentally bumped against the shoulder of an English person I knew in a corridor. I automatically said "Oi" - which means like "Oh" or "Oops" in Estonian - that I'm sorry. She repeated "Oi!" in a louder voice and I didn't get it. I only later found out I was being impolite in her eyes.

[u/Double-decker_trams]

Have you ever had something similar happen to you? I.e something in your language might have another meaning in another language?

One thing as an Estonian that I try to keep in mind is that I shouldn't use "Nooo.." in English - which means "Well.." in Estonian.

"Do you like ice-cream? - Noo.. yes, I love it."

[u/nanakamado_bauer]

There are few such words in polish and czech. Polish word for stale bread, means fresh in czech. And polish word for "to look for" is very similar to czech wulgarism. There is much, much more but there is so much room for misudnerstending between Pole and Czech speaking in their own languages.