Živio! - is used for the third person, singular, masculine gender Živjela! - is used for the third person singular, feminine gender Živjeli! - is used for the third person, plural Živjele!- is used for the third person, plural, feminine ( for example: let's take few names such as Mark, John, Ann, Susan, if you say Živio, it refers to John or Mark, Živjela refers to Ann or Susan, Živjele refers to Ann and Susan while Živjeli refers to Mark and John, or Mark and Ann, or to all of them

You say ''Živio!'' when you want to say 'Cheers' to male person, ''Živjela!'' to female person, ''Živjeli!'' is plural for both, males and females, ''Živjele!'' is plural but just for females.