1961, Gustav Bergmann, "Physics and Ontology," Philosophy of Science, vol. 28, no. 1, p. 2:
Philosophy during the first half of the century has taken the linguistic turn. Words are used either philosophically or commonsensically. Philosophical uses are literally unintelligible. The task is to explicate them by talking commonsensically about them. This is the fundamental idea of the turn.
2004, Paul Standish, "Europe, Continental Philosophy and the Philosophy of Education," Comparative Education, vol. 40, no. 4, p. 490:
The so-called linguistic turn. . . involved moving away from foundationalist assumptions of the primacy of logic and towards a more subtle recognition of the varied nature of language and of its deep influence, its pervasive implications across the range of human practices.