[metaxy2]

I wonder if "ent" evolved from "innit" under British colonization (or they both evolved from a common ancestor in British English).

[interestica]

Both probably from "is it not > isn't it" Canadian's have 'eh?' that serves basically the same function.

[metaxy2]

Americans (and I'd imagine the British) have "eh?" too, it's just not as common ("not bad, eh?"). Among Americans I feel like I've seen it more in casual written online conversation than in speech.