Positional Faithfulness and Vowel Harmony in Lubukusu: An OT Account

Abstract

In a number of languages, vowel harmony is generally initiated in certain positions that are psycholinguistically privileged such as root-initial syllables. Such positions not only trigger vowel harmony but may also block or fail to undergo vowel harmony process initiated elsewhere even when such a process is regular or expected in the phonology of the language. In the rule-based derivational analysis, such phenomenon was explained in serial rules that were often blind to outputs and could produce non-recurrent harmony types. Similarly, the derivational approach often failed to account for the privileged status of harmony triggering vowels. In a Positional Faithfulness (PF) account adopted in this study, it is argued that positional sensitive harmony is due to a high-ranked positional faithfulness constraint; IDENT-IO, (F) in an Optimality Theoretic Grammar. In this paper, based on Lubukusu (a Bantu language of Kenya), it is shown that vowel height harmony that is initiated in the root initial syllable can best be accounted for by recourse to constraint interaction in which positional specific faithfulness constraints dominates general faithfulness and markedness constraints. Vowels in root initial syllables may initiate or block vowel height harmony based on a universal constraint ranking for root-initial faithfulness. The analysis confirms that faithfulness constraints that are positional sensitive may be responsible for root induced vowel height harmony because such positions are psycholinguistically privileged in general language processing.