In the 17th century, "language work" was a programme for implementing theoretical linguistic knowledge (e.g. through language games). The objective was to enhance the status of German in the European context and equip it for use in all communicative domains. In this text, the author explicates the programme, its most important adherents, and all the areas in which it was used. The study demonstrates how reflected language practice made an important contribution to the establishment and standardization of New High German.