Let us now look at some of the differing ways in which linguistic varieties occur in speech communities, beginning with some large-scale variation and then working our way down to differences which occur on a smaller scale.

We will begin with societal bilingualism, the situation in which two or more distinct languages form the repertoire of a community. To explore the complex issues involved in a bilingual society it is interesting to look at one such situation in real historical and political depth. For this Canada will serve as a case study. (For general surveys, see the Further Reading.) We will then turn to those cases in which the society recognizes and names two distinct varieties of the same language as the repertoire, and speakers with more than one variety at their disposal switch or fluctuate between the alternatives. This leads us to the problem of relating the larger social pattern of the varieties to what individuals actually do in specific situations; and, even thornier, the problem of the actual linguistic relationship between varieties which people perceive as linguistically distinct.