expression, godan verb (-ku)
catch fire; be ignited; light
Literal sense: something combustible starts burning. Often used for accidental fires or when a flame appears.
ストーブに火がついた。
The stove caught fire.
マッチに火がつかない。
The match won't light.
expression, godan verb (-ku)
Figurative: emotions, controversies, or trends suddenly intensify or become popular. Often used with 感情, 論争, ブーム.
彼の一言で彼女の怒りに火がついた。
His remark ignited her anger.
SNSでその動画に火がついた。
The video went viral on social media.