These Wechselpräpositionen are also known as the "two-way prepositions." You could also think of them as double-use prepositions or change-up prepositions. To understand how that double-use functions, you need to already be familiar with the Akkusativ and the Dativ, which you are. First we'll look at the prepositions and then we'll walk through how they are used. Review the transcript, study the lesson and do the quizzes: https://www.newsinslowgerman.com/series/guts/21/transcript