1.
grandfather
The father of one's parent.
祖父は元気です。
My grandfather is doing well.
祖父は医者だった。
My grandfather was a doctor.
祖父から昔の話を聞いた。
I heard stories about the old days from my grandfather.
夏休みに祖父の家に遊びに行った。
I went to visit my grandfather's house during summer vacation.
祖父は今年八十歳になるけれど、まだとても元気で毎日散歩している。
My grandfather will turn 80 this year, but he's still very healthy and takes a walk every day.
祖父 is the formal term for one's own grandfather, used in polite or written contexts.
FORMALITY LEVELS:
- 祖父: formal (own grandfather)
- おじいちゃん: casual/affectionate
- おじいさん: neutral/someone else's grandfather
DISTINGUISHING GRANDFATHERS:
- 父方の祖父: paternal grandfather
- 母方の祖父: maternal grandfather
RELATED FAMILY TERMS:
- 祖母: grandmother (formal)
- 祖父母: grandparents
- 曽祖父: great-grandfather
USAGE NOTE:
Use 祖父 when speaking about your grandfather to others in formal situations. Use おじいちゃん when speaking directly to him or in casual contexts.