Diachrony and synchrony

Diachrony and synchrony are two complementary viewpoints in linguistic analysis. A diachronic – from δια- ('through, across') + χρόνος ('time') – approach, as in historical linguistics, considers the development and evolution of a language through history. In contrast, a synchronic approach – from Ancient Greek: συν- ('together') + χρόνος ('time') – considers a language at a moment in time without taking its history into account.

For example, a synchronic study of Middle English would focus on understanding how the language functioned at a given stage in its history. A diachronic approach, by contrast, studies language change by comparing different stages at different historical periods. The terms synchrony and diachrony are often associated with the historical linguist Ferdinand de Saussure, who considered the synchronic perspective as systematic but argued that language change is too unpredictable to be considered a system.

Conceptual development

The concepts were theorized by the Swiss linguist Ferdinand de Saussure, professor of general linguistics in Geneva from 1896 to 1911, and appeared in writing in his posthumous Course in General Linguistics published in 1916.

Saussure's teachers in historical-comparative and reconstructive linguistics such as Georg Curtius advocated the neo-grammarian manifesto according to which linguistic change is based on absolute laws. Thus, it was argued that ancient languages without surviving data could be reconstructed limitlessly after the discovery of such laws. In contradiction to his predecessors, Saussure demonstrated with multiple examples in his Course that such alleged laws are too unreliable to allow reconstructions far beyond the empirical data.