直ちに

1. Origins, structure, and basic meaning

• Structure: 直ちに (reading ただちに) is an adverb meaning to act at once, with no intervening delay.
• Basic usage: It is common in urgent, formal directions such as evacuating when an alarm sounds or reporting an abnormality.

2. Common pitfalls and similar expressions

• Urgency and register
  • 直ちに does not merely mean sometime soon; it calls for direct execution and fits official instructions.
• Contrast with 即座に
  • 即座に often highlights an on-the-spot response, while 直ちに strongly directs action to begin without delay.