This is the 218th most frequent Slovak word.
vtedy
"Vtedy" means "at that time" or "then" in English.
"Vtedy" here refers to a specific time in the past when the speaker lived in Bratislava.
Vtedy som ešte býval v Bratislave.
At that time, I still lived in Bratislava.
"Vtedy" is used to denote a particular moment in the context of a conditional or circumstantial action.
Urobila to, keď vedela, že vtedy tam nebudem.
She did it, knowing I would not be there at that time.
"Vtedy" emphasizes the specific moment at which the understanding occurred.