as soon as; the instant

や否や means that the instant one event occurred, another immediately followed. Attach it to a verb's dictionary form. It is formal and literary, common in writing, and the second clause is in the past.

Examples

• ドアを開あけるや否いなや、猫ねこが飛とび出だしてきた。

  Doa o akeru ya ina ya, neko ga tobidashite kita.

  The instant I opened the door, the cat darted out.

• その知しらせが伝つたわるや否いなや、町まちは大騒おおさわぎになった。

  Sono shirase ga tsutawaru ya ina ya, machi wa oosawagi ni natta.

  As soon as the news spread, the town was in an uproar.

Vocabulary in these examples

• ドア door
• 開ける to open
• 猫 cat
• その that (+ noun)
• 伝わる to be conveyed, to spread
• 町 town

Related patterns · Immediacy and timing

• 〜が早いか as soon as; no sooner than
• 〜なり as soon as; the moment
• 〜そばから no sooner than; as fast as (repeatedly)
• 〜を皮切りに starting with; beginning from