Japanese grammar

What does いったん~ば mean? Japanese grammar N2

いったん~ば means once… then.

Quick facts
Level (estimated, JLPT framework)N2
Structureいったん + Vば/Vたら
Romajiittan ba
Meaningonce… then

Forming it

Connectionいったん + Vば/Vたら

How to use it

States that ONCE A begins/happens, the consequence B is hard to avoid.

  • 「いったん~ば/たら」 = once A happens... 「いったん」 emphasizes that there is NO GOING BACK.
  • The second clause usually states a consequence that's hard to stop: 「いったん始めたら、最後までやるしかない」.
  • Different from 「一度」 (once, neutral): 「いったん」 emphasizes a turning point.

Examples

  • Once you begin, you should continue to the end.

  • Once you make a promise, you cannot easily change it.

Keep in mind

  • Emphasizes there is no going back.
  • The following clause is a hard-to-avoid consequence.

Common mistakes

  • Wrongいったん始(はじ)めるば、続(つづ)ける。

    Correctいったん始(はじ)めれば、続(つづ)ける。

    After いったん, a valid conditional form must be used.

Exam tips

  • 「いったん~ば」 = once A happens (hard to reverse); different from the neutral 「一度」.

Related patterns

All N2 grammar →