To be multilingual is to be utterly uninteresting; most of the world's population is multilingual. Interesting, however, is what happens when multilingualism leads to language contact. The resulting innovations can be anything from a mere exchange of words to a shift in grammar or to the birth of an entirely new language — and how to define these innovations is a question linguists are still trying to answer. In this episode, Aaron talks with Philipp Krämer, a professor of linguistics at the Free University of Berlin. They talk about how languages like Kiezdeutsch are classified, the contact situations of creoles and multiethnolects, and the many crucial ingredients needed for a dialect so rich as Kiezdeutsch to develop.