My mum's mum - My grandmother on my mother's side. My mum's dad - My grandfather on my mother's side. My dad's mum - My grandmother on my father's side. My dad's dad - My grandfather on my father's side.

This is how you would formally express these relationships: Instead of saying to someone: My mum's mum you say My maternal grandmother My mum's dad = My maternal grandfather My dad's mum = My paternal grandmother. My dad's dad =My paternal grandfather

English doesn't have a different word for mom's mom versus dad's mom. They are both called 'grandma'.

You can also use maternal grandmother ( mum's mum) paternal grandmother ( dad's mum) likewise... maternal grandfather paternal grandfather This would be for formal written English when mum's mum, or mother's mother is too informal (and rather clumsy). You wouldn't use these terms as forms of address! :-) Some families use different words for naming grandparents to help resolve the confusion ( and to give each grandparent a special name) - so , one grandma might be known as gran or grannie and the other known as nana . One grandad might be grandpa and the other papa, but this is not always the case, families are all different ! hope that helps :-) edit - whoops! Jura got there first :-)