Changes in Tai Dam Vowels

This paper aims to study changes in vowels in the Tai Dam language in three countries, namely, Thailand, Laos, and Vietnam. The vowel changes include regular sound changes and vowel replacements which have occurred because of language contact with majority languages. Some original vowels in Tai Dam in Thailand and Tai Dam in Lao have developed traits of vowels in Thai and Lao respectively, but only among a small group of young generation speakers. It is, therefore, predicted that the typical features of Tai Dam vowels such as the shortening of the long vowels *iː, *ɛː, *ɯː, *uː, *ɔː before *-k will be preserved. The vowel system of Vietnamese Tai Dam is the most conservative. Nevertheless, Vietnamese Tai Dam has been recently influenced by the Lao language because speakers of the Vietnamese Tai Dam language have been in contact with the Lao speech community more than in the past. Consequently, it is expected that phonological borrowing from Lao to Vietnamese Tai Dam will increase