(かぎ)

かぎ
noun
key, lock
1. key
A metal instrument for opening a lock.
(かぎ)(わす)れた。
I forgot my key.
(かぎ)をかけてから()かけた。
I locked up before going out.
(かぎ)をなくして(いえ)(はい)れなくなった。
I lost my key and couldn't get into my house.
2. key, clue
Something crucial for solving a problem.
成功(せいこう)(かぎ)努力(どりょく)だ。
The key to success is effort.
問題(もんだい)()(かぎ)()つけた。
I found the key to solving the problem.
この事件(じけん)(かぎ)(にぎ)っているのは、あの証人(しょうにん)だと(おも)う。
I think that witness holds the key to this case.

COMMON EXPRESSIONS:

  • (かぎ)をかける: to lock
  • (かぎ)()ける: to unlock
  • (かぎ)()める: to lock (alternate)
  • (かぎ)(にぎ)る: to hold the key (figurative)

COMPOUNDS:

  • 合鍵(あいかぎ): spare/duplicate key
  • 鍵穴(かぎあな): keyhole
  • 鍵盤(けんばん): keyboard (piano)
  • 鍵括弧(かぎかっこ): Japanese quotation marks「」

FIGURATIVE USE:
成功(せいこう)(かぎ) (the key to success) demonstrates how (かぎ) is used metaphorically for something crucial or decisive, similar to English "key."