I grow up in Beijing from a young age, but not native, so I speak 99% standard Mandarin. Beijing natives speak 90% standard. Born in the west, so I also understand Central Plain Mandarin.
Bragging aside, I must admit that the Cantonese part was just my very wild guessing according to my limited experience.
So from Cantonese to Mandarin "sub" is "shi"/10, "sei" is "si"/4. Although I can imagine "sub" being 10 because Cantonese does not have the "sh" sound so "sh" is substituted by "s", but how could "sub" to be must, what character is it? Translation by
@horse is "必" which is "Bi" in Mandarin, how would you pronounce "必" in Cantonese to something close to "sub" with the S?