Lability in Hittite and Indo-European: A Diachronic Perspective

Lability is defined as the possibility of a verb to enter a valency alternation without undergoing any change in itsform. Labile verbs were common in ancient Indo-European languages, including Hittite, which mostly features an-ticausative lability, with reflexive and reciprocal lability being less prominent. In Hittite, anticausative lability com-petes with the active versus middle voice alternation and predominantly affects active verbs. The Hittite data areimportant for a historical comparative perspective: a closer investigation suggests that lability is a late phenomenon,mostly occurring in New Hittite texts. The development of lability over time parallels similar trends observed inLatin and Ancient Greek and casts doubt on the reconstructability of lability in Proto-Indo-European.