Reconstructible grammaticalization processes in Cushitic (Afroasiatic) concern mainly the pronominal and verbal domains, markers of subordination, adpositions, question words and discourse particles. Starting with the sole representative of its Northern branch, Beja, this chapter investigates the various sources, targets and paths of 70 grammaticalization processes, seeks for comparable phenomena in three other branches of Cushitic-Central, Highland East and Lowland East-and compares them with the list provided in Heine and Kuteva's (2002) lexicon of the languages of the world, or with other literature about the languages of the Horn of Africa where Cushitic languages are spoken. Four main features of grammaticalization in Cushitic emerge from this investigation: (i) the nominal domain can be a source of grammaticalization, but this not (or hardly) the case for targets; (ii) auxiliaries, in particular the quotative verb which shows a vast array of functions, are often the source of the renewal and enrichment of the verbal system, but this is far less the case for verbless clauses as opposed to other Afroasiatic families, namely Semitic and Egyptian (Cohen 1984); (iii) quotative verbs have a strong tendency to grammaticalize at different levels of the language structure, verbs, complex sentences, discourse, including functions unattested in other genetic stocks; (iv) Cushitic languages show a pervasive semantic link between 'say' and 'purpose' at large.