(口语)(外)祖父用英文怎么说

"祖父" 用英语可以说作 "grandfather". "grand" 意思是 "祖先" 或 "高级"，"father" 意思是 "父亲". 因此 "grandfather" 就是 "高级的父亲" 或 "祖先的父亲" 的意思.

例句:

My grandfather is a retired teacher. (我的祖父是一名退休的老师)
I have a close relationship with my grandfather. (我和我的祖父关系非常亲近)
My grandfather passed away last year. (我的祖父去年去世了)