1. In the central and southern mountains, Mon-Khmer tribes, known as Lao Theung or midslope Laotians, predominate.

2. Not like the Mon-Khmer native to the Peninsula, the Daic populations were considered to be migrants from the north.

3. The O Du language belongs to the Mon-Khmer group. Children find it hard to learn O Du, as the Kinh language is used at school and Thai is spoken at home.

4. A family of languages of southeast Asia once dominant in northeast India and Indochina, including Mon-Khmer and Munda.

5. Here we present the Y chromosome data of 1,652 individuals from 47 populations of Mon-Khmer(MK) and Hmong-Mien(HM), which distribute primarily across Southeast Asia and extend into East Asia.

6. In this study, we compared the Y chromosome diversity of the Peninsular Daic to those of Chinese Daic and the Mon-Khmer populations to reveal the origin of the Peninsular Daic populations.

7. This thesis finds the phonetic types of the prefixes of Mon-Khmer languages by investigating the phonetics of the prefixes of Khemu, De'ang, Mang, Bulang, Wa and Cambodian.

8. This paper focuses on the analysis of the morphological forms of personal pronouns in some Mon-Khmer Languages. The main forms are flexion in the grammatical categories of person, number and gender.