"As a successor of József Budenz, József Szinnyei was a dominant figure, in the late nineteenth and early twentieth centuries, of research on the Finno-Ugric languages in Hungary and of the associated teaching tasks at university level. He was an adherent of the Neogrammarian approach whose attention encompassed, in addition to the study of the other Finno-Ugric languages, Hungarian historical linguistics (especially historical phonology and the history of certain morphological formatives). In his research work as a linguist, historical studies were clearly dominant. His sphere of interest was centred upon the history of Hungarian, its Finno-Ugric background, and its comparison with related languages. In his comparative studies, he professed that language was continually changing but, since etymological studies could detect regular sound correspondences in the words of languages of the same family, sounds did not change randomly but in a systematic manner. He emphasized that sound law type changes could only be established on the basis of words that certainly, or at least highly probably, belonged together."