決心

1. Origins, structure, and basic meaning

• Structure: 決心 (reading けっしん) is a noun and suru-verb for firmly making up one’s mind after considering alternatives.
• Basic usage: It suits consequential choices, such as resolving to take over a family business or refusing to abandon a settled resolve.

2. Common pitfalls and similar expressions

• Strength of commitment
  • 決心する usually carries an intention to act and is stronger than making a routine choice.
• Stating the content
  • The chosen action can appear before the noun, as in 家業を継ぐ決心, or before と決心する.