や
(Ya)
at the moment of / as soon as (literary).
Connection rules
- +V dict-form + や / や否や.
- +Literary / classical 'as soon as'.
- +や alone or や否や (same meaning).
Examples
1.
彼は家を出るや、走り出した。

Kare wa ie o deru ya, hashiridashi ta.
The moment he left the house, he ran off.
「at the moment of / as soon as (literary)」
2.
目を開けるや否や、眩しい光が差し込んだ。

Me o akeru ya ina ya, mabushii hikari ga sashikon da.
The moment I opened my eyes, bright light poured in.
「at the moment of / as soon as (literary)」
Practice
As soon as the cat saw the mouse, it jumped at it.
猫はネズミを___、飛びかかった。
Romaji also accepted