The Highland East Cushitic (HEC) languages, including Burji, Hadiyya, Kambaata, Sidaama, and Gedeo, are spoken by over twenty million people in southern Ethiopia. Although their historical relatedness has long been recognized, Proto-Highland East Cushitic (PHEC) and Proto-Northern Highland East Cushitic have not previously been reconstructed in a comprehensive and systematic way. This dissertation addresses that gap.
Drawing on a comparative database of over 8,500 lexical entries from 23 East Cushitic languages, this study reconstructs major aspects of the PHEC sound system, lexicon, and selected morphological items, and traces how a common ancestral language diversified into five distinct but related modern languages. It identifies the regular sound changes that connect them. Along the way, it reveals discoveries such as the systematic glottalization of sounds, the reversal of consonant positions to allow feasible sound sequences, and evidence of long-standing contact with neighboring Omotic and Oromo languages that shaped the HEC sound systems in subtle but traceable ways.
The study also reconstructs shared morphological patterns, such as verb derivations, case systems, and plural formations. On the basis of combined phonological and morphological innovations, it refines proposals for the internal subgrouping of HEC. The analysis supports Burji as the earliest split and groups the remaining languages in a Northern HEC branch.
The accompanying lexical database is made openly availableand links source forms, cognate sets, and reconstructions, to support transparency and reproducibility in comparative African linguistics.
