Vietnamese would rather use kinship terms than proper name. Kinship terms can be classified into four groups as follow:
1. Terms used to identify not to address (e.g. chồng, vợ, mẹ vợ, cha vợ, mẹ chồng, cha chồng…)
2. Terms used to address not to identify (e.g. chú sáu, anh hai, cô tư,…)
3. Terms used to address when they follow another kinship term (e.g. anh/em rể, em rể/ dâu, con/cháu rể/dâu,…)
4. Terms used to identify and address (e.g. cha, mẹ, chú, bác, cô, dì, anh, em, con,…)
In theory, the term “con” is only used between parents and children. However, in reality, the Vietnamese tend to use this term instead of “cháu” when talking to “ông, bà, chú, bác”. In Vietnamese perspective, it seems that only the term “con” is intimate enough to express the closeness. In family discourse, kinship terms must follow a fixed rule but in social discourse, these terms are used rather flexibly. The core meaning of this term is changed when used in social discourse; therefore, they the social ranked cannot be identified through kinship terms. In family discourse, Vietnamese addressing is based on rank of age, in which age of parents are taken as the starting point. To people who are older than the father, Vietnamese people call him “bác” and call her “cô/bác”. To people who are younger than the father, we can call him “chú” and call her “cô”. To people who are older than the mother, we can call him “cậu/bác” and call her “bác/dì”. Finally, to people who are younger than the mother, Vietnamese people would like to call him “cậu” and call her “dì”. Thus, in such cases, we can easily identify the social status of participants based on address terms.
Though these terms are called kinship terms, they are also used in social communication. The following example can illustrate this point.
“Chị Dậu vội vàng…chạy đến đỡ tay cầm thừng của người cai lệ”
“Cháu van ông, nhà cháu mới vừa tỉnh, ông tha cho!” (Phan, 2009, p. 405)
Through this example, we can see that people can use kinship terms both in family and social interaction; thanks to which social status and emotion of the speaker can be realized.