Many modern-day Chinese Filipinos have traditional names with one syllable like Lim, Tan, Sy, and so on. However, early Chinese Filipino families took on the complete name of their patriarch, thus their names had three syllables. These are truly Filipino surnames and don't exist anywhere else in the world. Their names were transcribed using Spanish orthography in effect during the 19th century.

If you are wondering why so many names end in -co and -ko, it is because co was a title of respect given to someone like an elder, or an older brother. However, Co was also a valid name so that it would be hard to say whether the "Co" in the name was part of the original Chinese name or was an honorific. Generally speaking, if it is at the end it would have been an honorific.

An example of this is Cojuangco. Their patriarch was Co Chi Kuan, who was addressed respectfully as Co Kuan Co (one given name dropped). Co Kuan Co eventually became Cojuangco.

You might find it interesting that there are a few names with a similar structure (like Canseco and Polanco) in Mexico. Could these families have been started by Chinese Filipinos who settled in Mexico as a result of the Manila-Acapulco galleon trade?

hi my surname is chansuyco, what is chansuyco mean?