написать открытку по английскому Dear Grandmq

мне нужно бабушку с дедушкой

Речь идет о бабушке? Тогда grandma или grandmother.Dear Grandmother, I am writing you a letter. We have not seen each other for a long time. How are you? I am fine. I'm walking, playing with my friends. Our family misses you. When do you come? We will wait for you very much. With best wishes, your family and friends.