This study focusses on affixation and auxiliaries in Igbo, drawing on data mainly from Onicha (Onitsha) Igbo. It identifies prefixes, suffixes, interfixes, circumfixes, super/suprafixes, extensional suffixes and auxiliaries in the variety of Igbo studied. The work is presented in two sections: Section 1 discusses affixation, while Section 2 is focused on auxiliary verbs. Section 1 contains five chapters. Chapter 1 is a general introduction that provides some background information regarding O? ni?cha [make sure this word is correct i.e. represented in the spelling of the language, and not just Onicha] Igbo and the speakers of the lect. Chapter 2 an overview of affixation as an important word formation process in world languages. Chapter 3 is the morpho-syntactic analysis of inflectional affixes. Chapter 4 discusses the morphosyntactic characteristics of derivational affixes, while Chapter 5 is concerned with the morpho-syntactic as well as the semantic charateristics of verbal extensions in Igbo. Section 2 is a sole chapter which discusses in a systematic manner the different types of auxiliary verbs, their uses and the effect of their co-occurrence with perfective verb forms.