1, Nana's basic explanation: grandma, nanny, abbreviated from nanny, grandma and grandma. Nana: Idiot, slang word, probably from bananas, related to sexual organs. British sound: [n: n], American sound: [nn, n: n].

2. Bilingual example: Nana and her father and her brother and sister. Grandma and grandpa have dad and his brother and sister.