1. Full name: Patthida Bunchavalit                      2. Sex: Female

3. Date of birth: 11/12/1981                                4. Place of birth: Nakhon Phanom province, Thailand

5. Admission decision number: 2859/QĐ-XHNV, Dated: 02/11/2017

6. Changes in academic process: Adjustment of the doctoral thesis title from “The error of pronunciation of Vietnamese tones of the Viet Kieu in Nakhon Phanom Province, Thailand” to “Variants of Vietnamese Tones over the Viet Kieu Generations in Nakhon Phanom Province, Thailand” accoding to Decision no.1450/ QĐ-XHNV on 20/08/2020.

7. Official thesis title: Variant of Vietnamese Tones over the Viet Kieu Generations in Nakhon Phanom Province, Thailand

8. Major: Vietnamese Linguistics                                    9. Code: 62 22 01 02

10. Supervisors: Assoc.Prof.Dr. Vu Kim Bang and Dr.Nguyen Ngoc Binh

11. Summary of the new findings of the thesis:

The Vietnamese tonal system of the Viet Kieu generations in Nakhon Phanom province, Thailand was affected by both internal and external factors. Specifically, it was affected by both the simplification mechanism of its own tonal system, and the language interference phenomenon that occurred due to language contact with the Thai, Isan and Lao tonal systems. To compare with the Vietnamese tonal system, thanh Huyền is the only tone which has no variation, while the thanh Hỏi, thanh Ngã and thanh Nặng tones have variation because of both internal and external factors. The tones thanh Ngang and thanh Sắc have variation because of external factors only. Therefore, this information can be used to predict the variation of Vietnamese tonal characteristics of the Viet Kieu in Nakhon Phanom province in the future in the following ways: thanh Ngang will have no variation in intonation but it will ahve a variation in pitch which  has a lower pitch than Ngang in original Vietnamese; thanh Huyền will have no variation both in intonation and pitch; thanh Sắc will tend to still retain two new variants which are: 1) down-up like thanh Chặt tạ va5 (low-down-up) in Thai language; 2) flat like thanh 5 [22] in Isan language in the syllables ending with unvoiced plosive consonant but both of them have lower pitch than thanh Sắc in original Vietnamese; thanh Hỏi tend to still retains a new variant is low-down like thanh Huyền or thanh Ệch2 (low-down) in Thai language; thanh Ngã will tend to  retain traits of both of original variants and new variants (down-up, up, up-glottalization, up-down, up-down-glottalization), but glottalization in the new variants will completely lose the glottalization phenomenon or it will appear in only some variants; thanh Nặng will tend to completely lose original variants and finally it will result in 3 new variants: 1) low-down like thanh Huyền or thanh Ệch2 (low-down) in Thai language; 2) low-flat like thanh 5 [22] in Isan language; 3) low/medium-flat-up like thanh Nặng in the syllables ending with unvoiced plosive consonant in original Vietnamese, but will completely lose glottalization phenomenon in all of variants[AMD-A1] [AMD-A2]

12. Practical applicability (if any): An error analysis in pronouncing other tones to whom studies foreign language.

13. Further research directions (if any): An error analysis in pronouncing Vietnamese tones of Thai who studies Vietnamese or in pronouncingThai tones of Vietnamese student who studies Thai as a foreign language.

14. Thesis-related publication:

1) Bunchavalit Patthida (2019), “The Vietnamese Tones Variation in Closed Syllable of the Viet kieu in Nakhon Phanom Province, Thailand”, Proceedings of Fifth International Conference on Linguistics and Language Studies (ICLLS 2019), School of Humanities and Languages of the Caritas Institute of Higher Education, Hong Kong, pp.6-13.

2) Bunchavalit Patthida (2019), “Contrastive Analysis in Phonetics Characteristics of Thai and Vietnamese Tones”, Proceedings of the Conference on Asian Linguistics Anthropology (CALA 2019), the Pannasastra University of Combodia, Siem Reap, pp.224-251.