ABSTRACT Lability is defined as the possibility of a verb to enter a valency alternation without undergoing any change in its form. Labile verbs were common in ancient Indo‐European languages, including Hittite, which mostly features anticausative lability, with reflexive and reciprocal lability being less prominent. In Hittite, anticausative lability competes with the active versus middle voice alternation and predominantly affects active verbs. The Hittite data are important 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 in Latin and Ancient Greek and casts doubt on the reconstructability of lability in Proto‐Indo‐European.
Guglielmo Inglese (Wed,) studied this question.