Off the top of my head, Danish "De" (practically never used), German "Sie", Chinese "您", French "vous", Spanish "usted" are formal ways of addressing

The incredible story of the Scrabble savant from Christchurch.
More on Nigel:
https://fivethirtyeight.com/features/what-makes-nigel-richards-the-best-scrabble-player-on-earth/
http://scrabblestudylog.blogspot.com/2009/08/nigel-richards-article-by-stefan-fatsis.html…