On the Origin of Philippine Vowel Grades

The concept of vowel grade by which morphological features in some Indo- European languages are signaled by change in the quality of the vowel of a given form has long been recognized. More recently, the term has also been applied to the variation in vowels that occur in some case-marking prepositional forms in Austronesian languages. The purpose of this paper is to demonstrate some of the processes by which vowel grades developed in some Philippine languages. These processes include what has been referred to elsewhere as vowel-grade harmony, an assimilatory process by which the vowel of one case-marking preposition copies that of another. Noun phrases in many Philippine languages are commonly described as being introduced by phrase markers that specify certain syntactic and semantic features of the noun phrase they introduce. These are typically unstressed clitic forms having a CV or CVC shape. However, the quality of the vowel varies from language to language. Thus, in Ivatan, the forms that introduce common noun phrases all have an u vowel, while those that introduce personal noun phrases all have an i vowel; in Tagalog the forms that introduce common noun phrases all have an a vowel, while those that introduce personal noun phrases all have an i vowel, like Ivatan. Recognizing that the similarity in vowel quality of "phrase markers" in these languages is commonly the result of vowel-grade harmony and not necessarily the result of regular phonological change provides an explanation for the multiple irregularities that are found in attempting to reconstruct the protoforms of "phrase markers.