During participatory development different professional groups with different professional languages meet. They have to communicate about the future software in a profound way. To enable that, a common way to talk about the future software has to be developed, relating concepts of the use context and concepts of software development. An example of the development of such a project language is given and the relevance of this for design is argued for. To support the development of a project language a toolkit is provided in which methods are compiled that respects the creative side of ordinary language.