Despite occasional difficulties, there is a general impression of mutual intelligibility among many speakers of different dialects of English. This is one of the criteria used in the study of dialects, or dialectology, to distinguish between two different dialects of the same language (whose speakers can usually understand each other) and two different languages (whose speakers can’t usually understand each other). This is not the only, or the most reliable, way of identifying dialects, but it is helpful in establishing the fact that each different dialect, like each language, is equally worthy of analysis. It is important to recognize, from a linguistic point of view, that none of the varieties of a language is inherently “better” than any other. They are simply different.

From a social point of view, however, some varieties do become more prestigious. In fact, the variety that develops as the standard language has usually been one socially prestigious dialect, originally associated with a center of economic and political power (e.g. London for British English and Paris for French). Yet, there always continue to be other varieties of a language spoken in different regions.