How to treat people in positions of authority in Germany
If you speak German, it will be easier for you to move, study and work in Europe. German is the mother tongue of 130 million people in that continent. It is recognized as the official language in Germany, Austria, Belgium, and Luxembourg. And it is a part of the official languages in Switzerland and the Principality of Liechtenstein.
However, more than knowing the language, it is about understanding the right way to communicate with native German speakers. It is about understanding the difference when talking to a child, an adult or with a person in a position of authority. The general rule says that adults or people with authority must be addressed using their last name and the equivalent in German to the pronoun “usted” in Spanish. It can be rude to do it differently.
Taking that into account, the pronoun “usted” in Spanish is equivalent to Sie in German. Older people or people in a position of authority should be addressed as “Mister or Miss + last name”, which would correspond to Herr or Frau + last name in German. Despite formalities in German, an organization might change their culture and start using the pronoun “tú”, which corresponds to Du in German. There are exceptions in some cases when older adults or people in positions of authority get closer to other people and ask to be called by their first name.
Formality depends on the circumstances, the social circle, or the culture of the organization. It is always better to be safe than sorry, so it is always recommended to be formal when starting a conversation, and to then build a connection as it develops.