Modal particles and discourse markers: Two sides of the same coin?

In this introductory chapter, we situate the investigation of the intersection between modal particles (MP) and discourse markers (DM) within the wider context of categorization work in linguistics. We examine the definitions provided in the literature for DMs and MPs, and review different reasons for the possible confusion between the two classes, among which their functional proximity and diachronic relation. The overview of the contributions to the volume shows that it is nevertheless possible to precise whether and to what extent DMs and MPs constitute one single class. According to the parameters taken into account, authors will tend to group them into a single (pragmatic) class or into two distinct classes.