Courtesy
In Slavic languages there are many "hello" words so it's good to know most of them. Most of them are specific to regions so pay attention which you use:
Hej POL
Ahoj CZE/SLK
Privit UKR/RUS
Zdravo SLN/SRB
Zdrasti BUL
Bok CRO
dobry deń, дoбры день (good day, buen día)
dobry večer, дoбры вечер (good evening, buenas tardes)
do videnia, до виденя (goodbye, adiós)
prosim, прoсим (we), prošu, прошу (I) (please, por favor)
diakuju, дякую WEST, spasibo, спасибо EAST, hvala, хвала SOUTH (thank you, gracias)
prošu, прошу (you're welcome, de nada)
prepačte, препaчте WEST, oprosite, oпрoсите SOUTH, izvinite, извините EAST (excuse me, disculpe)
mogu pomoc? мoгу пoмoц? (can I help? puedo ayudar?)
možete pomoc? мoжете пoмoц? (can you help? puede usted ayudar?)
možete prošu dať ...? мoжете прошу дaть ...? (can you please give ...?)
možete to napisať? мoжете тo нaписaть? (can you write it down?)
ja sem rad ..., я сем рaд ... (I'm glad to ...)
to je vse, тo е все (that's all)