消す

1. Origins, structure, and basic meaning

• Structure: Spelling: 消す. Reading: けす. Core meaning: to erase; to turn off.
• Basic usage: Representative examples: 黒板の古い文字を消す / 部屋を出る前に明かりを消しました.

2. Common pitfalls and similar expressions

• Erasing and switching off
  • 消す can mean erasing writing or a trace and switching off a light or flame. Distinguish it from the intransitive 消える, in which something disappears or goes out.