floor · stairs

1. Origins, structure, and basic meaning

• Structure: The on reading is かい, and the kun reading is きざはし. It has 12 strokes. It appears in words for physical stairs and abstract stages.
• Basic usage: 階段 is read かいだん and 段階 is read だんかい.

2. Common pitfalls and similar expressions

• 階段 / 段階
  • 階段 means stairs or staircase and is read かいだん. It refers to physical stairs used to move between floors.
  • 停電でエレベーターが止まり、十階まで階段で上った。 means “The power outage stopped the elevator, so I climbed the stairs to the tenth floor.”
  • 段階 means stage or step and is read だんかい. It refers to an abstract stage or step in a plan or task.
  • 計画はまだ準備の段階にある。 means “The plan is still in the preparation stage.”