Explaining the difference between formal and informal ways of address to English speakers is quite difficult. Even if student can explain when to use what, they usually have trouble using the correct form even in simple, common phrases.
This reference sheet is useful for beginners as well as intermediate students; it can be used to introduce the concept and common forms, and later on to add different cases and uses.
On one handy page that the students can refer back to again and again, the sheet summarizes the different forms of du, ihr, and Sie (nominative, dative, accusative, possessive), lists common phrases in the different forms, and gives students some additional information and guidelines. With the guidance of the teacher, students write down in what situations formal vs. informal is used.
This page is suitable to accompany any textbooks or materials the teacher may be using.