key

1. Origins, structure, and basic meaning

• Structure: The on reading is けん, and the kun reading is かぎ. It has 17 strokes. It appears in words for a door key, a key point, and musical keys.
• Basic usage: 鍵 is read かぎ, and 鍵盤 is read けんばん.

2. Common pitfalls and similar expressions

• 鍵 / 鍵盤
  • 鍵 means key or key point and is read かぎ. It can refer to a door key or the key point in solving a problem.
  • この発見が問題を解く鍵になった。 means “This discovery became the key to solving the problem.”
  • 鍵盤 means keyboard or keys and is read けんばん. It refers to the keys of an instrument such as a piano.
  • 子供がピアノの鍵盤を一つずつ押して音を確かめた。 means “The child pressed the piano keys one at a time to hear their sounds.”