1. Background

Ablaut, as illustrated by the vowel alternations in/sing/:/sang/:/sung/, is a familiar phenomenon to speakers of English, and of many other Indo-European languages. However, in the more than 900 members of the Austronesian (AN) language family this type of morphological device is exceedingly rare. 1 In conducting linguistic fieldwork in northern Sarawak from April to November 1971, the writer collected data from some 41 AN language communities, and in perhaps half of these it was found that ablaut was an active morphological device in the voice system of the verb. More specifically, ablaut was found to be present in the following languages, some of which are represented by multiple dialects: 1) Kelabit-Lun Dayeh, 2) Berawan, 3) Kiput, 4) Narum, 5) Miri, 6) Bintulu, and 7) Melanau (a dialect chain extending from Balingian in the north to Kanowit, some 120 km. up the Rejang River in the south). Some languages show a less fully developed, and others a more fully developed system of ablaut alternations, as will be explained below. Table 1

This paper was written while I was a fellow at the Institute of History and Philology, Academia Sinica, Nankang, Taipei, January-December 1994, and was presented at the Seventh International Conference on Austronesian Linguistics held at Noordwijk aan Zee, Holland, 27-31 August 1994.1 am grateful to the National Science Council of the Republic of China, and to the staff of the Institute of History and Philology for making my stay in Taiwan both pleasant and productive. Thanks go to Randy J. Lapolla for help of various kinds, and to Paul JK Li for providing information on morphophonemic alternations in Sediq. Last, but not least, I owe a debt of gratitude to the two anonymous referees whose comments led to real improvements in the presentation, and to Alexander Vovin for his assistance in preparing the final copy.