息

1. Origins, structure, and basic meaning

• Structure: 息, read いき, refers to breath taken in and let out.
• Basic usage: In 坂を走って上ったので息が切れた。, running up the slope left the speaker out of breath.

2. Common pitfalls and similar expressions

• Being out of breath
  • 息が切れる describes becoming short of breath, for example after exertion. Here 切れる is not about an object being cut.
• Breathing in and out
  • 息を吸う means to breathe in, and 息を吐く means to breathe out. 吐いた息 refers to breath already exhaled.