This study is based on an analysis of videos and transcripts of five films Fric-frac, Circonstances atténuantes, Le Jour se lève, La Règle du jeu and Hôtel du Nord. These films are examples of planned and artificial language. The book looks at the evidential value of these data and assesses the extent to which stereotyped and scripted language can contribute to an understanding of spoken Parisian usage by looking at phonetics, syntax, discourse, lexis and pragmatics. By comparing traditional research carried out by scholars in the nineteenth century and earlier with Parisian data collected and analysed by twentieth-century researchers, the work attempts to identify the salient features that both script-writers and actors in these films considered to be characteristic of social-group differences at that time.