neck · head

1. Origins, structure, and basic meaning

• Structure: 首 denotes the neck or head; its on-reading is しゅ, and its kun-reading is くび.
• Basic usage: Standalone 首 refers to the neck and also appears in an expression for dismissal, while 首都 means a national capital.

2. Common pitfalls and similar expressions

• 首 / 首都
  • 首: This noun means the neck, while the fixed expression 首になる means to be fired from a job. Example: 規則を何度も破り、彼は会社を首になった。
  • 首都: This word refers to the capital city of a country. Example: その国の首都は大きな川のそばにある。