What does ～たとたん mean? Japanese grammar N2

Forming it

How to use it

The moment A happens, B occurs, outside the speaker's expectation.

• 「Vたとたん」 = the moment A happens, B: 「ドアを開けたとたん、猫が飛び出した」.
• The second clause MUST be something that happened unintentionally — not used for intentions, invitations, or commands.
• Within the "no sooner… than…" group: 「とたん」 (unexpected) — 「か～ないかのうちに」 (nearly simultaneous) — 「次第」 (once A is done, B is done deliberately).

Examples

• ドアを開(あ)けたとたん、冷(つめ)たい風(かぜ)が吹(ふ)き込(こ)んできた。

  The moment I opened the door, cold wind blew in.

• 電話(でんわ)をかけたとたん、バッテリーが切(き)れてしまった。

  The moment I made the call, the battery died.

Keep in mind

• Connects to the た form.
• The following clause is unintended and has already happened.

Common mistakes

• Wrong家(いえ)に着(つ)いたとたん、休(やす)もう。

  As soon as I get home, I'll rest.

  Correct家(いえ)に着(つ)いたとたん、疲(つか)れが出(で)てきた。

  The second clause must be something that happens unintentionally; it is not used for intentions.

• Wrongドアを開(あ)けるとたん、猫(ねこ)が逃(に)げた。

  As soon as I opened the door, the cat ran away.

  Correctドアを開(あ)けたとたん、猫(ねこ)が逃(に)げた。

  Must attach to the た form.

Exam tips

• 「たとたん」 = the moment A happens, B (unexpected); attaches to the た form.

Related patterns

• ～か～ないかのうちに
• ～次第
• ～たかと思ったら