Genetic and areal distribution of grammaticalization processes are being studied in the majority of languages around the world. Grammaticalization study is however a very new area of research in Ethiopian languages. This work then is a contribution to the study of grammaticalization in the Ethiopian Semitic languages. The book deals with the genetic distribution of the process of grammaticalization of the morpheme ge which makes a striking appearance in nearly all the 16 Ethiopian Semitic languages considered in the study. From a noun meaning 'land' or 'time', the morpheme ge polygrammaticalizes into spatial and temporal markers (adpositions, conjunctions, and subordinators) taking four major pathways: (1) LAND > PLACE > LOCATIVE > TEMPORAL (2) TIME > TEMPORAL > CONDITIONAL, and CAUSE (3) TIME > COMITATIVE (4) TIME > DISJUNCTIVE CONJUNCTION ('or'). Its focus on a single morpheme in a genetic unit with multiple pathways of grammaticalization (some of which are remarkable) will make the book of special interest to all linguists interested in language change in general and in Ethiopian Semitic languages in particular.