Abstract
This article for the first time provides a corpus-based investigation of the variation and change in the system of German pronominal forms of address in the 19th and early 20th century. Today's opposition between formal Sie ('Siezen') and informal Du ('Duzen') originates in the 18th century; Sie mainly replaced formal forms of address with Ihr ('Ihrzen') or Er/Sie ('Erzen'). The data for our analyses are taken from two corpora of private correspondence - patient letters and emigrant letters - with a total of 2,748 letters by 788 writers. Contrary to previous findings that had mainly been based on grammar book accounts and/or anecdotal evidence, our results show that the use of the formal Sie pronoun was still rather common when addressing parents in the second half of the 19th century and even the early 20th century. There was no abrupt collapse of the four-tier system of pronominal address to today's two-tier system but in some regional non-standard varieties of German a three-tier system continued to be used throughout the 20th century. The addressee, the linguistic context and a writer's changing emotional state prove to be relevant factors of intra-individual variation. The data also suggest that male writers and experienced writers lead the change from formal Sie to informal Du in addressing parents. Overall, the observed change in pronominal address can be interpreted as a prototypical invisible-hand process.