Scholars summing up research on question tags, such as McGregor (1995: 91) or Nässlin
(1984: 11) state that tags originally became subject of research mainly in connection with
various grammatical theories, serving as evidence for or against different theories or concepts.
Later receiving interest from sociolinguistics, attention was devoted mainly to gender
differences in usage of question tags (Dubois, Crouch 1975)