Morphologically triggered tonogenesis in Dinka and Nuer: A working hypothesis
Abstract: In W. Nilotic languages such as Nuer and Dinka, various grammatical properties are signalled primarily by introducing complex and layered changes to the stem. These changes involve modification of vowel quality, quantity, tone, and consonantal mutation: W. Nuer lɛ́p ‘tongue.SG.NOM’, lɛàp ‘tongue.SG.GEN’, lé̤e̤f ‘tongue.PL.NOM’. However, related languages from a more conservative W. Nilotic sub-branch Burun suggest that the ancestral language had a rich inventory of affixes which were lost in Nuer and Dinka. For example, Surkum Ɂʌ̀m-bi ‘eat-AP’ (Ɂàm ‘eat.TR’) vs Nuer cà̤m ‘eat.AP’ (càm ‘eat.TR’); Mayak Ɂin- ʌth “intestine-SG” (Ɂin “intestines”) vs Nuer ciɛ̀n “intestine.SG” (ciín ‘intestines.PL). Historically, the stem-modifying morphological operations seen in Dinka-Nuer are relics of processes related to the presence and loss of the old suffixes, such as compensatory lengthening, intervocalic lenition, vowel harmony (Andersen 1988, 1990, 1999). The loss of suffixes also correlated with emergence of such properties as vowel phonation contrasts (breathy vs creaky/modal) and three degrees of length in Dinka and Nuer. In this talk, I propose that loss of suffixation also introduced new complexity to the old W. Nilotic tonal system, bringing about emergence of contour tones. Burun languages typically have only two tonemes (H and L) but, as I will argue using Mabaan as example, partial attrition of suffixes has already became a contributing factor for the appearance of falling tones in these languages. Full attrition of suffixes in Nuer and Dinka has taken this process a step further. I suggest that the same tonal rules that apply in Mabaan over a span of a root and a partially atrophied suffix, apply within the stem in Nuer and Dinka, and are responsible for generation of some falling tones. Another source of falling tones is found in Nuer where high tones are realized as falling over all modal (but not breathy) vowels.