caution · commandment

1. Origins, structure, and basic meaning

• Structure: 戒 has 7 strokes, the on-reading かい, and the kun-reading いましめる. 警戒 (けいかい) means vigilance; 戒める (いましめる) means to admonish or warn.
• Basic usage: 警戒 concerns watching for something dangerous or suspicious; 戒める concerns warning oneself or another person against wrongful behavior.

2. Common pitfalls and similar expressions

• Watching for danger and warning oneself
  • 野生動物に警戒しながら describes walking while watching for wildlife. 警戒を強めた means increased vigilance against suspicious calls.
  • 私を戒めた describes a father admonishing the speaker not to treat promises lightly. 自分を戒めている means warning oneself not to forget past failures.