For “you” the German language has both and an informal word: Sie and Du. It is typical for German colleagues, even those who work well together and have known each other for many years to use the Sie-Form. The Knigge – Germany’s best known books on proper behavior, first pubished in 1788 by Baron Adolph Knigge – recommends the Sie-Form in the work context.
Knigge considers it appropriate to reject the offer of the Du-Form from a work colleague if one feels surprised or thrown off balance. For accepting the informal Du is a commitment to a level of personal friendship and trust one may not wish. Knigge recommends a polite response: “Your offer honors me. Thank you. However, I feel more comfortable using the Sie-Form, and prefer to continue using it, also out of respect for you (Sie).“
Maintaining a certain respectful distance to others is considered a sign of respect in the German culture. A famous example is the relationship between two of the best-known soccer tv-commentators, Günter Netzer (a former star German soccer player) and Gerhard Delling (a respected tv sports journalist).
Their conversational-type commentaries during half-time and after games are enjoyed by millions due to both their expert analysis and relaxed interaction. Yet, on camera they address each other with the formal Sie, even though Netzer was a groomsman (witness) in Delling’s.
