[TeacherSumi]

"PO" and "OPO" are unique form of Tagalog/Filipino language words were in you will have to include this in your conversation/greetings/questions if you are talking to an elder.

Example:
The American way/Western language-----In Tagalog
Good morning!-------------------------Magandang umaga po!

Nice to meet you.--------------------Kinagagalak ko po kayong makilala.
or I'm glad to meet you. Kinagagalak(glad) ko pong
makilala(meet) ka(you).

What is your name?----------------------Ano (what)po ang inyong(your)
pangalan (name)?
or Ano po ang pangalan ninyo?

It makes the sentences longer but using "PO" and "OPO" will also gives an impression from the person (who greets) that he/she is respectful to elders.