A German who rejects a drink is not just being shy or polite but does not want to drink.For some cultures it is uncommon to see teenagers order a beer at restaurants and pubs.Remember that the legal drinking age in Germany is 16 for beer and wine and 18 for spirits.Punctuality: Don’t turn up late for an appointment or when meeting people.Names: It is polite to address everyone by their family name and "Sie." Do not leave off double-barreled names, such as Frau Müller-Weber.Names are inserted into conversation after every few sentences.
Garbage: Germans are extremely environmentally conscious and separate their garbage to facilitate recycling.
Placing knife and fork on the right side of the plate in parallel is a signal to the waiter that you have finished and that the plate can be cleared away.
Knocking: When entering an office, it is common to knock first and then enter the room immediately.
Du and Sie: In private, the older person suggests using the informal "du" to the younger person.
In the business world, the higher ranking person–regardless of age and sex–would always be the one to suggest switching to "du." A nice intermediate step is to address a person by their first name but then use the formal "Sie." Always ask, however, before you decide to take this step.