regret

1. Origins, structure, and basic meaning

• Structure: 憾 has 16 strokes and the on-reading かん. 遺憾 (いかん) and 痛憾 (つうかん) express regret.
• Basic usage: 遺憾 means regret about an unfavorable result or something not turning out as hoped; 痛憾 means profound regret or sorrow.

2. Common pitfalls and similar expressions

• Expressing regret and its degree
  • 合意に至らなかったことは誠に遺憾です means that failing to reach an agreement is deeply regrettable. 遺憾の意を示した means expressed regret over a rule violation.
  • 痛憾の極みだ expresses profound regret that an accident could not be prevented. 深い痛憾の意を表した means expressed deep regret over the outcome.