SYNCHRONY AND DIACHRONY IN HISTORICAL SOCIOLINGUISTIC STUDIES
The article deals with the evolution in the study of language change in the 19th – 21st centuries in relation to treatment of the synchrony :: diachrony dichotomy – from interpretation of diachronic and synchronic approaches as mutually exclusive to the application of more integrated approach proposed by historical sociolinguistics, where diachrony and synchrony are regarded as crossover processes, where one cannot be understood without the other. We believe that the revolution in the interpretation of the opposition of synchrony / diachrony was the work of William Labov, who developed a radically new method of dealing with this problem by proposing to study changes in the process of their development using quantitative methods and thus set a new direction for the development of historical linguistics. Labov’s followers further developed his ideas and proposed a new explanation to the spread of language change, now known as lexical diffusion. Currently, it is generally accepted that all language changes are of two types. Either they are explained in accordance with the hypothesis of regularity that was put forward by the Neogrammarians in the second half of the 19th century, or following the hypothesis of lexical diffusion first proposed by William Wand.