This study examines the changing patterns of usage of Scottish Gaelic and English in the northern Scottish counties of Sutherland and Caithness during the period 1698-1901. The study explores the way these patterns resulted from processes found in different social situations. It is concluded that although the shift from Gaelic to English was not felt with the same impact everywhere, it probably followed a number of stages: (1) an increased use of English words or idioms within Gaelic; (2) an associated decline in the purity of Gaelic used; (3) an increased interest in acquiring and using English; and (4) differential language use among generations, social classes, and domains of usage. It is suggested that while the decline of Gaelic may have been apparent through geographical retreat of the language border, it was more determined by the widespread substitution of English for Gaelic as the daily language. Twenty-eight references and a six-page bibliography are included. (MSE)