Who says that sing-songy language is necessary? Kids actually crave being taken seriously like adults and teachers who do that are often well liked! My actual

Who says that sing-songy language is necessary? Kids actually crave being taken seriously like adults and teachers who do that are often well liked! My actual question is … how to develop good humor and playfulness in kids? Some people grow up with somewhat stunted senses of humor it seems. Is there something one can do? Research?