感激

1. Origins, structure, and basic meaning

• Structure: The noun and する verb 感激 (かんげき) means being deeply moved by kindness, sincerity, or an unexpected event.
• Basic usage: A completed reaction is 手紙を受け取り感激した, while 感激して礼を述べる connects that feeling to a response.

2. Common pitfalls and similar expressions

• Being deeply moved
  • It means an intense emotional response often involving gratitude or joy, not surprise alone.