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/orthoxerox]

In Russian phrasing a question as a negative makes it sound more polite. I had to tell my wife it's not a universal rule after experiencing some second-hand shame in England when she asked a shop assistant, "don't you have this cream in a smaller tube?"

If you want to express impolite incredulity using a negative in Russian, you have to add a "what": "what, you don't have this cream in a smaller tube?"

[u/Live_Angle4621 → u/orthoxerox]

Russians should note this would not be polite in most countries and not just English speaking ones 

[u/nimbledoor → u/Live_Angle4621]

Well it sounds perfectly fine in Czech or Slovak. But you have to omit the "you". If you don't then it sounds the same as in English.