か〜ないかのうちに

This grammar expresses that something happens almost immediately after another action or event begins or ends. It emphasizes how quickly the second event follows the first, often catching us by surprise or indicating a narrow window of time in which something occurs. It is typically used in narrative or descriptive contexts to convey a rapid succession of events. The clause before か/ないかのうちに describes the first action or situation, and the main clause describes what happens in that brief moment just after. The action in the main clause is often completed quickly due to the timing implied by かのうちに.