Manners are made up of trivialities of deportment which can be easily learned if one does not happen to know them.
Emily PostNothing is less important than which fork you use. Etiquette is the science of living. It embraces everything. It is ethics. It is honor.
Emily PostChildren are all more or less little monkeys in that they imitate everything they see. If their mother treats them exactly as she does her visitors they in turn play "visitor" to perfection. Nothing hurts the feelings of children more than not being allowed to behave like grown persons when they think they are able.
Emily PostThe fact that slang is apt and forceful makes its use irresistibly tempting. Coarse or profane slang is beside the mark, but "flivver," "taxi," the "movies," "deadly" (meaning dull), "feeling fit," "feeling blue," "grafter," a "fake," "grouch," "hunch" and "right o!" are typical of words that it would make our spoken language stilted to exclude.
Emily Post