aremost common, but very rare when referring to a grandparent in person.In speech,  Grandpa  and  Grandma  aresometimesused in the  UnitedStates  and  Canada .In  Britain ,  Ireland , States,Australia, NewZealand  and  Newfoundlandand Labrador ,  Nan ,  Nana ,  Nanna ,  Nada , Nanny ,  Gran  and  Granny  andother variations are often used for grandmother