“Hosebeast” and “Bozo” like everybody else.
It was the same for me. But my maternal grandmother was a school teacher, and she’d get on me for not pronouncing the “d”. So I’d get in the habit of calling her “Grandma”. Then I’d go visit my paternal grandmother, and call her “Grandma”, and she’d say, “Would you stop that?” I think I could get away with using the same names for both sets because the two sets weren’t usually in the same room despite living fairly close to each other (no hostility, just didn’t socialize much, and we’d almost always visit them separately).
No kids of my own, but I have nieces, and thanks to their biological grandparents on both sides being divorced and remarried they have four sets of grandparents. Here’s the names I know:
My mom and stepdad: Grannie Annie and Bop (I’m not sure how my oldest niece came up with “Bop”)
My dad and stepmom: Grampa Dean and Lorna (I guess she doesn’t get the “Gramma” title, which isn’t surprising, since my sisters and I refer to her as “Dad’s wife” rather than “stepmother”. See, she’s the younger woman our dad left our mom for …)
Brother-in-law’s dad and stepmom: Papa and Nana
I’m not sure what BiL’s mom and stepdad are called, as they’re the only set that doesn’t live here in the same town, and thus are seen less often.
Did. Grandma and Grandad Surname, on both sides. (Without the surname when addressing them, obviously.)
We called my Mom’s parents Siti (means grandma in Arabic) and Gidi (means gandpa in Arabic) since they came from the Middle East. I never knew my Dad’s dad but his name was Finis, my Dad’s mom we called her Sanie. Our kids call my parents Nana and Granddad or to tease my Dad our youngest will call him Dangrad or Dangie. As for Bobo’s parents they are Grandma & Grandpa or they like to tease them and call them G-Ma & G-Pa.
Both sets are Nan and Pop. If clarification was needed when I was younger, Nan and Pop <last name>.
Now about the only case when clarification is needed is when one of my grandmothers calls and I have to tell my parents, so I usually end up saying ‘your mom’ or ‘<other parent’s> mom’.