Wikipedia said:Languages and cultures with more specific kinship terminology than English may distinguish between paternal grandparents and maternal grandparents. For example in the Swedish language there is no single word for "grandmother"; the mother's mother is termed mormor and the father's mother is termed farmor.
English doesn't follow this rule. Mandarin Chinese does follow it with "wai gong" (Grandpa on mother's side), "wai po" (Grandma on mother's side), "yie yie" (Grandpa on father's side) and "nai nai" (Grandma on mother's side). What else?