Filipinos are really polite! You have to be polite to your elders (parents, parents' friends, grandparents etc.) If you're not polite, they will think you are rude. There's always an alternate for a polite version.
Yes:
Oo
Opo (Polite)
No:
Hindi
Hindi po (Polite)
Thank you:
Salamat
Salamat po (Polite)
So you see, you add a 'po' somewhere in your sentence. For example:
Kakain na po tayo
We're going to eat
Magandang umaga po
Good morning
YOu only use the polite words with someone who is older than you, excluding friends and cousins.