Variants:
The grammar structure んばかりに expresses that someone or something acts as if about to do something, or conveys an intense degree of emotion or action that is on the verge of happening. It paints a vivid, often dramatic picture of a situation where something appears to be about to occur – though it may not actually happen.
It attaches to the negative stem (未然形) of verbs, effectively using the classical negative auxiliary ん (= む, expressing intention/likelihood).
Group 1 (五段) verbs: Replace the final -u with -a + んばかりに
Group 2 (一段) verbs: Drop る + んばかりに
んばかりに is a literary and expressive pattern typically found in written language, novels, formal descriptions, and dramatic narration. It is rarely used in casual conversation.
The key nuance is that the action described by the verb before んばかりに does not actually happen – it just appears as though it will. It emphasizes the intensity of the situation.