People from all over the world gather here. It can be roughly divided into aborigines, Minnan people or mainlanders or Hakkas.

People who speak Minnan dialect in Taiwan Province Province call their parents' father: grandpa's mother: grandma.

So you won't hear mainlanders call grandpa, grandma, grandpa or grandma, grandpa or grandma.

If you call grandparents to old people who are not relatives,

That's a polite address.

Not limited to people anywhere.