1 The Tonal Structure of Nkoroo Nominal Constructions 1 Akinbiyi Akinlabi, Bruce Connell and Ebitare Obikudo Rutgers University, York University and Delta State University. 1. Introduction 1.1 The Language The Nkoroo people are located in Opobo/Nkoroo local government area of Rivers State, Nigeria. Nkoroo is an endangered minority language spoken in Nkoroo town alongside Defaka (another severely endangered language) and in some other smaller villages. In official records, Nkoroo is the name of the people and the dialect they speak but the people refer to themselves and their dialect as Kirika, so named after their ancestor who led the migration to their present location. Kirika has no semblance with Okrika, which is the anglicised form of wa kirik meaning 'we are the same' in Okrika dialect. Linguistically, Nkoroo has been classified as an Eastern Ijoid dialect (Jenewari, 1989; Williamson and Blench, 2000) alongside the dialect cluster of Kalabari, Ibani and Okrika. 1.2 The Key Claims This paper presents a comparison of the tone patterns found in Nkoroo nominal compounds and proclitic plus host structures with the tone patterns found in other types of Noun Phrases. We reveal that a crucial output tone pattern separates Nkoroo nominal compounds and proclitic+host structures from these Noun Phrases. Viewed from a processorial perspective, the output tone patterns of Nkoroo nominal compounds and proclitic+host structures reveal a cocktail of processes, including the possible postulation of a floating tone, tone spreading processes, and tonal metathesis. However the result of each process is always the same (a fixed output pattern), regardless of input tone structure. This paper argues that an adequate account, whether rule based or constraint based, must capture this apparent conspiracy. We define tonal conspiracy as a phenomenon in which several independent tonal processes in a language result in the same tonal outcome. It is as if the language requires a specific tonal melody on the output, and it does not matter what the input is. Nkoroo is a two-tone plus downstep language. The examples in (1) illustrate this lexical contrast. (1) Tonal contrast in Nkoroo oki (HH) ‘take’ oki (H ↓ H) ‘swim’ oki (HL) ‘swordfish’ Hoewever, the overall pitch pattern in nominal compounds shows that Nkoroo may be moving in the direction of an accentual system, with fixed tonal melodies associated with particular morpho-syntactic categories. Other scholars, including Jenewari (1977) and Williamson (1978, 1986) have made similar “accentual” observations about Ijoid languages in general, and Harry (1987) has made this observation about Nkoroo.