Language is a central cognitive human ability and humankind’s most important communication organ. Although people’s brains are all very similar, there were, and still are, thousands of different languages, which are also constantly evolving. What are the common elements in this diversity? What fundamental categories – such as syllables or words – can be shown to exist everywhere and at all times? By studying the evolution of language over lengthy periods and analysing the structure and dynamics of German regional languages, the researchers in the LOEWE research cluster are seeking to identify and provide empirical evidence of fundamental linguistic categories. Taking these “universals” as their starting point, they are researching the relationship between language and the brain with a view to improving the diagnosis and therapy of language disorders.