Po is a term that is used to show respect. That is why:
- "Kumusta ka?" is INFORMAL and is used among friends or when addressing a younger person.
- "Kumusta po" or "Kumusta ka po?" is FORMAL and is used when addressing an older person. In fact, the best way to say it is "Kumusta po kayo?" using the formal/plural you (kayo) instead of the informal/singular you (ka).
- "Kamusta" is a popular but wrong way of spelling "kumusta."
One thing you got wrong is that it goes the other way around. Kumusta ka is the informal way while Kumusta po is the formal way. Also, Kumusta po can also be written as Kumusta ka po. There won't be any difference in the basic meaning of the phrase. The word 'na' can also be added before the 'ka', like "kumusta ka na", or "kumusta ka na po".
to an older sibling, parent or figure of authority: Kumusta ka po?
to a friend or acquaintance" Kumusta ka?
I dont speak Tagalog but i know that much. If i am off with my definition please correct me.
friend/younger person- Kumusta po?