This book presents the morphological description and the syntactic roles of verbal functional categories of Diddessa Mao, an Omotic language spoken in western part of Ethiopia. In his description, the author identifies morphological realizations of verbal functors like agreement, aspect, tense mood and negative. In Diddessa Mao subject agreement is expressed by reduced forms of pronouns that occur as proclitics. Such grammatical categories as aspect, tense and mood are indicated by suffixes.In the linear ordering of affixes, the order of tense, aspect and mood markers is fixed. Subject agreement and negative markers; however do not have fixed position. The agreement markers move from one host element to another within verbal clauses whenever the clauses expand by adding more constituents. The pronouns and the subject agreement markers also make a three- way grammatical number distinction. This is a linguistic feature which has not been reported in Omotic studies. These and a lot of other issues discussed in the study make the work important for linguists, language students and for those who are interested in the study of Omotic languages.