The modal system of the Igbo language
In spite of the number of studies on mood and modality in Igbo, it is mainly the category of mood that can be found in most grammar books of the language, both old and new. This state of affairs could be as a result of the lack of a morphosyntactic systematization of modality that is comparable to the works on mood in the language; but it could also be as a result of the under analysis of the verbal morphology of the language in relation to modality. This paper is an initial effort at such systematization. The focus is on the use of such verb morphologyrelated structures as single root verbs like t o si "should/ought to" verb+NP verbal structures lke nwe ike "can" and verbal suffixes like _ nwu "able" and r i. r i. "compulsion" for the expression of modality in the Igbo language. The use of these structures to cover the whole spectrum of deontic and epistemic meanings argues for their recognition as constituting the verb morphology related modal system of the language. This attribute also distinguishes them from the modal particles and other structures that have been categorized as "periphrastic forms" (Igwe 1987; Nwigwe 2003) but which are here categorized as "peripheral modals" because they can only be used to express mainly epistemic but not deontic modal meanings. A further attribute of the identified core structures of the Igbo modal system is some level of interaction with aspect that is comparable to that confirmed in Abraham (2001, 2002) whereby the deontic meanings tend to coalesce with perfective aspect, while epistemic meanings tend to coalesce with imperfective aspect. This quality of a systematic interaction of the modal meanings with aspect, which cannot be confirmed for the "peripheral modals" further strengthens the conclusion that the identified verbs and affixes constitute the core of the Igbo modal system