History of linguistics (19th century) ; History of linguistics (20th century) ; Inner speech ; Wahrnehmung und Sprache; Perception and language; Speech perception (psycholing.) ; Sprachfehler; Language attrition (pathol.) ; Language loss (pathol.) ; Sprachverlust (pathol.) ; Speech pathology ; Cercle linguistique de Prague; Prague Linguistic Circle; Prague school