The story
- Hokkien · borrowed from姦恁娘母 /奸恁娘母
- English todaykan ni na bu
From Hokkien 姦恁娘母 /奸恁娘母 (kàn-lín-niâ-bú / kàn-ní-nâ-bú). The variant kan ni na beh likely results from a shortening of the last two syllables in 姦恁娘母的 /奸恁娘母的 (kàn-lín-niâ-bú-ê, “fuck your mother's”) from bú-ê to bé.
Etymology from Wiktionary, CC BY-SA 4.0.