Formal:
* Magandang araw po. Kumusta po kayo? (Good day. How are you?)
* Magandang hapon po. Kumusta po kayo? (Good afternoon. How are you?)
* Magandang gabi po. Kumusta po kayo? (Good evening. How are you?)
Informal:
* Kumusta ka? (How are you?)
* Musta? (Short for "Kumusta ka?")
* Kamusta ka? (Another way to say "Kumusta ka?")
More casual:
* Uy, kamusta? (Hey, how are you?)
It's also common to add a "po" at the end of sentences when speaking to someone older or in a position of authority, as a sign of respect.
Here are some ways to respond:
* Mabuti naman po. (I'm good.)
* Okay lang po. (I'm okay.)
* Ayos lang po. (I'm alright.)
* Mabuti naman po kayo? (How are you?)
The best way to choose the right greeting depends on the context and your relationship with the person you are speaking to.