blue · green

1. Origins, structure, and basic meaning

• Structure: The on readings are せい and しょう, and the kun readings are あお and あおい. It has 8 strokes. It appears in words for the color blue and green traffic signals.
• Basic usage: 青 is read あお and 青信号 is read あおしんごう.

2. Common pitfalls and similar expressions

• 青 / 青信号
  • 青 means blue and is read あお. It refers to blue, as in the sea, and can also denote a green traffic light.
  • 海の青と白い雲の対比が美しかった。 means “The contrast between the blue sea and white clouds was beautiful.”
  • 青信号 means green light or go-ahead and is read あおしんごう. It refers to a green traffic light or figurative approval to proceed with a plan.
  • 青信号になってから横断歩道を渡った。 means “I crossed the street after the light turned green.”