Some historians believe that in order to find out where Tai people came from, we need to find out where the language came from originally. Linguists have traced the roots (the beginning) of the modern Thai language, or the proto-language, to an area of southern China.

In 1953, a linguist named A. G. Haudricourt claimed that the Red River valley of China is where the Tai languages originated. He that the proto-Tai language was centered there until about 1100 AD and then spread out away from that location, eventually reaching modern day Thailand. Even today, if you visit the Chinese province of Guangxi you can find people speaking languages very similar to Thai. In addition to this, Indigenous (or native) people of Guanxi also share many cultural practices with Thai people, like the believe in city ghosts (ผีเมือง) and similarities in legends and folklore.