Halfmann, Jakob. 2025. The diversification of Indo-Iranian and the position of the Nuristani languages (Beiträge Zur Iranistik 54). Wiesbaden: Reichert Verlag.
This book offers a new approach to the long-standing problem of the genealogical affiliation of the Nuristani languages, a small group of closely related languages spoken in the Eastern Hindu Kush, within the Indo-Iranian subgroup of Indo-European. This topic is approached via a step-by-step examination of the crucial isoglosses, while taking into account more sample data than was available to previous researchers. The author concludes that the Nuristani languages were likely historically more closely affiliated with the Iranian than the Indo-Aryan subgroup, though they must have been isolated from the Iranian continuum early on and subsequently have come under intense contact influence from Indo-Aryan languages.