Quick answer
Grandfather in Tagalog is "lolo".
Pronunciation
Say it as loh-loh.
Usage and cultural notes
Lolo is the affectionate word for grandfather and is used widely in family conversations.
Use lolo for your grandfather and add po when speaking respectfully.
Example sentences
Si Lolo ang nagkuwento tungkol sa pamilya.
Grandpa told a story about the family.
family story
Lolo, salamat po.
Grandpa, thank you.
respectful thanks