What is Spanish for grandmother and grandfather?

Here are the Spanish words for grandmother and grandfather:

* Grandmother:

* Abuela (formal, common in most of the Spanish-speaking world)

* Yaya (informal, common in some regions, especially Spain)

* Abuelita (informal, diminutive of abuela, often used endearingly)

* Grandfather:

* Abuelo (formal, common in most of the Spanish-speaking world)

* Yayo (informal, common in some regions, especially Spain)

* Abuelito (informal, diminutive of abuelo, often used endearingly)