Who, what; forms questions asking information about a person.
Siya cha (man or maa)?
Who are they?
Siya man a mantotoro?
Who is that who is teaching?
Siyes si-katho?
Who is he? [esp. as an abstract question, e.g. the Son of God or the descendant of Abraham]
Siyay ngaran mo?
What is your name?
Ngoy ngaran to?
What is its name? [for things other than a person]
Ampay siya ka aya?
So who are you? (i.e. So who do you think you are?)