Cayuga (In Cayuga Gayogo̱hó:nǫ’) is a Northern Iroquoian language of the Iroquois Proper (also known as "Five Nations Iroquois") subfamily, and is spoken on Six Nations of the Grand River First Nation, Ontario, by around 100 Cayuga people.

There were at one time two distinct dialects of Cayuga. One is still spoken in Ontario, the other, called "Seneca-Cayuga," was spoken in Oklahoma until the 1980s.

There are two varieties of Cayuga. The Lower Cayuga dialect is spoken by those of the Lower End of the Six Nations and the Upper Cayuga are from the Upper End. The main difference between the two is that the Lower Cayuga use the sound [gj] and the Upper use the sound [dj]. Also, pronunciation differs between individual speakers of Cayuga and their preferences.

There are 5 oral vowels in Cayuga, as well as four long vowels, [i:], [a:], [o:], and [e:]. Cayuga also has 3 nasalized vowels, [ẽ], [õ], and [ã]. Both [u] and [ã] are rare sounds in Cayuga. Sometimes, the sounds [u] and [o] are used interchangeably according on each individual speaker's preference. After long [e:] and [o:], an [n] sound can be heard, especially when before [t], [d], [k], [g], [ts], and [j].

Song In (in hangul 송인, in hanja 宋仁) was a civil official in the mid-Goryeo era who became the intermediary founder of the Jincheon Song clan. His highest post was munha pyeongjangsa (문하 평장사). This was the highest government position in the period. Song In was responsible for administration, judicial affairs and economy in the district.

As he performed meritorious deeds during the King, he was conferred with Chanhwagongsin and Jincheonbaek. Baek was a position of politicians who were responsible for administration, judicial affairs and economy in the district. As the government created him Jincheonbaek, his family started regarding Jincheon as their origin. Hence, the family origin became Jincheon Song.

When he was in the position of Sangsanbaek, he tried to be just and fair in all the administrative affairs and strived to enhance the welfare of his people. He also focused on education for the youth and courtesy for people, which made his district famous for most excellent behaviors in the nation. After that, the people have long paid tribute to his feats.