According to " Language in Society", An introduction to Sociolinguistics, by Suzanne Romaine, the standard language is normally acquired at home as a mother tongue and continues to be used throughout life. Its main uses are in familial and familiar interactions. In Thailand, the standard language is acquired from home, school and public arenas. Different parts of the country acquire different local languages. However, people have to learn the standard language in order to be able to communicate with the rest of the people from the different parts of the country. It is used in school, governmental office, bank, university, and every public arena. People from Bangkok and its vicinities mostly acquire standard language from home as a mother tongue. Unlike people from other parts of the country who acquire local language as a mother tongue. Both local and standard languages serve the same purpose. They are used in normal conversation, with family member, friend, and other familiar interaction or with the normal domains such as school, governmental office, etc.
To serve the high status domains or people, Thai people are required to use higher function language, which is "Kam Racha Sap"/ /. Kam Racha Sap is considered Higher function. According to "language in Society" An Introduction to Sociolinguistics, by Suzanne Romaine, people do not acquire higher function language at home as a mother tongue. They acquire the higher function language in school or they are tough in some institutions. Not everyone can use high function language properly. People must have knowledge of using this language. Not all people have knowledge of using Kam Racha Sap. It is tough only in school and some of Thai language institutions. It is used to serve higher status of domains and people. Thus, Kam Raha Sap is considered higher function language.
According to National Dictionary, 1982, p.682 ( Translated by Author ), Kam Racha Sap means special language used for communicate with the King and Royal family. Later it is also used with the monk and the governor. According to " Thai Language Grammar", p.157 ( Translated by the author ), Kam Racha Sap means language for the king or the royal language. In the past, Racha Sap was used for talking to or mentioning about the king or the royal family. It was for normal people talking to the king and the royal family not the king and the royal family talking to each other. Later, it is also used with governor and also including the official language. Hence, Kam Racha Sap, now, means the language used with 1. The king and the queen, 2. the royal family, 3. monk, 4. governor, and 5. formal situation. With different status also use different words.
Thai people have been using Kam Racha Sap for centuries. There are none of any research found the beginning of the use of Kam Racha Sap. However, there was an official announcement of using Kam Racha Sap in the period of King Pra Barom Trai Loknart, in 1458 during Ayuthaya period. It...