In this short paper we address two central questions prompted by the developments of the current Covid-19 crisis: (1) Why do some practice in crisis situations change quickly and radically while others remain apparently stable? (2) How does the fact that some practice changes are meant to be only temporary affect their performance and to what extent is it possible to go back to the earlier practices in a meaningful sense after the crisis? We answer these questions with recourse to the structures of practices. On the one hand, there are the internal organizing principles of the focal practice and on the other hand there are the external relations of the focal practice to other practices around it. Based on our argument we develop an agenda for future research on the structures of practices.