行為

1. Origins, structure, and basic meaning

• Structure: 行為 is read as こうい and is a relatively formal noun for a human act or conduct being identified and evaluated.
• Basic usage: Its content appears in 人を傷つける行為, while an adjective characterizes it in 親切な行為.

2. Common pitfalls and similar expressions

• Evaluation comes from context
  • The noun is not inherently negative: a harmful act is condemned, while a kind act receives thanks.
• Focus on an act
  • The examples identify what someone did rather than describing the person's entire character.