Language settings question - how to not use English

A user writes,

May I know how to change the English language to Cebuano? We are using two languages Obo Manobo and Cebuano instead of English.Your help is greatly appreciated.

I believe what you are trying to do is set the Language 2 of your book to Cebuano instead of English? Such that the front/back matter will contain Cebuano instead of English?

You can access the collection settings from the Collection tab and change the language settings from there: