This article proposes a new categorization of confirmation-seeking question tags, based on how the use of such tags is restricted in relation to the preceding clause, the anchor. The focus is on a category labelled grammatically-dependent question tags (GDQTs). Earlier research has claimed that almost only English has such question tags, but this article presents and compares data on GDQTs from more than ten languages, and suggests a hierarchy for features of grammatical dependence in question tags: polarity < tense < number/person < (semantic) gender (possibly also < verb substitution). The GDQT structures vary in different ways: all GDQT languages have negative GDQTs, but not all have positive GDQTs; verb substitution is not always applied and constant polarity instead of reversed polarity is also found.
A detailed record of normal-reversed-polarity transition obtained from a thick loess sequence at Jiuzhoutai, near Lanzhou, China
