祖父

1. Origins, structure, and basic meaning

• Structure: The kinship noun 祖父 (そふ) means one's grandfather, the father of either parent.
• Basic usage: It can be the subject of everyday actions or the source in 祖父から教わる.

2. Common pitfalls and similar expressions

• One's grandfather
  • It denotes one's parent's father, not an elderly man in general.