Igbo Root-Outward Vowel Harmony in Feature Spreading and Stem-Affixed Form Faithfulness Proposals

This article explores the viability of using feature spreading and stem-affixed form faithfulness approaches to account for the attested patterns in Igbo root-outward vowel harmony. The analysis shows that the former undergenerates the attested patterns and makes incorrect predictions about the direction of the harmonic feature for Igbo verbs with affixes at either end of the root vowel, whereas the stem-affixed form faithfulness approach is shown to provide a more parsimonious account of the attested patterns following the morphological structure of Igbo verb roots and their affixes. This leads to the conclusion that the superiority of the stem-affixed form faithfulness proposal to the feature spreading account lies in the fact that the former captures straightforwardly the principal empirical generalization about the evident asymmetry existing between Igbo verb roots and affixes forbidding root vowels from alternating to agree with affix vowels even if this leads to incomplete harmony.