Dialect levelling

Dialect levelling or leveling (in American English) is the process of an overall reduction in the variation or diversity of features between two or more dialects. Typically, this comes about through assimilation, mixture, and merging of certain dialects, often by language standardization. It has been observed in most languages with large numbers of speakers after industrialisation and modernisation of the areas in which they are spoken. Dialect levelling has been defined as the process by which structural variation in dialects is reduced, "the process of eliminating prominent stereotypical features of differences between dialects", "a social process [that] consists in negotiation between speakers of different dialects aimed at setting the properties of, for example, a lexical entry", "the reduction of variation between dialects of the same language in situations where speakers of these dialects are brought together", "the eradication of socially or locally marked variants (both within and between linguistic systems) in conditions of social or geographical mobility and resultant dialect contact", and the "reduction... of structural similarities between languages in contact", of which "interference and convergence are really two manifestations". Leonard Bloomfield implicitly distinguished between the short-term process of accommodation between speakers and the long-term process of levelling between varieties and between the social and the geographical dimensions. On the geographical dimension, levelling may disrupt the regularity that is the result of the application of sound laws. It operates in waves but may leave behind relic forms. Dialect levelling and Mischung, or dialect mixing, have been suggested as the key mechanisms that destroy regularity and the alleged exceptionlessness of sound laws. Dialect levelling is triggered by contact between dialects, often because of migration, and it has been observed in most languages with large numbers of speakers after the industrialisation and the modernisation of the area or areas in which they are spoken.