Nobody on the planet waves like the British Royal Family. Instead of shaking the hand, they keep it vertical, and twist the wrist slightly. Nobody seems to be sure how or why it started, but it's here to stay. Prince George has been able to do it since he was three years old. That implies some form of decorum training is given from the moment a young Royal is able to speak and understand.
Elocution and selection of language is taught from an early age, too. The delivery of speech as given by the Royals belongs to a different age and is more refined than even the richest and most reserved of Britain's upper class. George will always say 'lavatory' instead of toilet', 'settee' instead of 'sofa' and 'dinner' instead of lunch. The Royals are not like normal people, and so they don't talk like them.