My mum finally read Mamoribito - The One Who Protects. I was a little worried she might baulk at all the naughty words - Peter, the main character, swears a hell of a lot (most of it much worse than that). But she had no complaints about that. Instead, she admonished me for using 'gotten' instead of 'got.' I suppose Brits are supposed to use 'got' - but I've lived in Japan so long I think I've gotten used to using it the American way.
On the other hand, 'gotten' is becoming more widespread in the UK. In fact, both got and gotten existed as far back as Middle English, and pre-dates US usage.
Not that I want to argue with me mum.....
