I propose a few epistemological and methodological reflexions to account for intercultural daily communication. These reflexions emerged during a sociological research in Mendoza, Argentina, with Huarpes Indigenous students at the University of Cuyo. I observed that Indigenous people became quasi ethnographers of diverse environments. To make intelligible their classmates’ behavior, and to account for their own behavior, Huarpes follow, in diverse environments and interactions, public rules of meaning. The objective of this paper is twofold: (a) to stress the methodological scope (...) of ordinary communication and ordinary reasoning in order to study understanding between people from different groups and categories, and (b) to contest a kind of pessimist standpoint in social sciences and philosophy according to which the use of ordinary language reduces possibilities for understanding. Interviews, participant observation in natural situations, and a review of literature about language and understanding are the basis of this paper. (shrink)