This book provides a concise description of the pronominal empty categories of Gamo, an Omotic language spoken in Ethiopia. The principles of the GB Theory are relied on to identify the distribution and interpretation of pronominal empty categories in the language. Gamo is found to be a pro-drop language as subject NPs can be covert in a tensed clause. The covert NP subjects, pro, can be recovered from subject NP agreement elements attached on verbs. Its object NPs are not allowed to be covert. The absence of object NP AGR elements is the cause for this. Moreover, nominal features are absent in Gamo subordinate clauses, which in turn restrict the presence of pro in a complement clause except the relative and participial clauses. It is also discussed that pro can semantically interpreted as definitely or arbitrary based on the presence or absence of AGR elements. As the discussion of the analysis reveals Gamo pro fills in a theta or a non-theta position. PRO occurs in the subject position of infinite clauses. Its content is recovered when an antecedent NP or an implicit argument that is believed to have the status of pro is considered.