The English word 'understand' can be translated into Tagalog in at least two ways:

 

intindi
understand

unawa
comprehend

Naiintindihan mo ba?
Do you understand (it)?

Naiintindihan mo ba ako?
Do you understand me? (use with people your own age or younger)

Naiintindihan po ba ninyo ako?
Do you understand me? (use with older people)

Naiintindihan kita.
I understand you. (casual)

Naiintindihan ko po kayo.
I understand you. (to older people)

Hindi ko naiintindihan.
I don't understand.

Hindi ko naiintindihan ang sinasabi mo.
I don't understand what you're saying.

Nagkakaintindihan ba tayo?
Do we understand each other?

Nauunawaan po ba ninyo ang nilalaman ng dokumentong ito?
Do you understand the contents of this document? (to older people