Eipä kestä. = "You are welcome." Ole hyvä. = 1) "You are welcome." 2) When you hand something over to someone or you open a door, you can say: "Ole hyvä". Olkaa hyvä (respectful form). = Ole hyvä. You say "olkaa hyvä" when you are talking to an old person, to your professor etc.

Yes, that's true, Timo. I didn't mention "olkaa hyvät", because it is not used so much. Kielikello (published by The Institute for the Languages of Finland) says that "olkaa hyvät" is "maybe a bit obsolescent" ('ehkä hieman vanhahtava'). https://www.kielikello.fi/-/oletteko-kuullut-teitittelysta-

https://en.wiktionary.org/wiki/olkaa_hyv%C3%A4t#Finnish , just to point out that there is also "olkaa hyvät" (not often used, plural form of olkaa hyvä). But most of the time "eipä kestä" or "ole hyvä" is the way to go.

Paljon kiitoksia :) So when talking to more people I say "olkaa hyvä" or "eipä kestä", when to one - I can use all forms, I understood :)

Yes, "olkaa hyvä" is more polite. As I said, you use it when you are talking to an old person, to your professor etc. When you are talking to more than one person, you say "olkaa hyvä". Literally "ole" and "olkaa" are imperative forms: ole (singular imperative) (olla = to be) olkaa (plural imperative)