Some idioms translate between dialects very well. “Dead” as used by some in the UK (whichever part of the country Sue Townsend sets Adrian Mole at least) and “wicked” as used by those in the northeast of the US could pretty much be interchanged without losing meaning, since they both seem to mean roughly the same thing - very/extremely. Wicked good/dead good. Dead annoying/wicked annoying.
However, in the context of “couldn’t be arsed to ___” the UK arsed is the equivalent of “bothered” in the US. But I’m about 90% sure “Am I bothering you?” doesn’t translate to “Am I arsing you?”
Is there a term for word pairs that are the equivalent in two dialects only in certain forms and/or tenses of the words?
Dunno the answer to your question, elfkin477, but the Adrian Mole books are set in Leicester, in the (north) east Midlands. At some point there is a mention of Ashby-de-la-Zouch, which is a nearby suburb.
Your question uses two different meanings of ‘bother’ (to ‘be bothered’ as in to make an effort and to ‘be bothered’ as in to be inconvenienced).
In any case, the idiom/colloquialism isn’t translatable into other forms; it only exists as “can’t be arsed” - or to put it another way, ‘bother’ is only replaceable by ‘arse’ in this very specific structure, because it isn’t a complete redefinition of the verb.
“Phew! I’m pooped!” means roughly the same as “Phew! I’m tired!”, but “Do you find this sort of work tiring?” cannot (sensibly, at the time of writing) be replaced by “Do you find this sort of work pooping?”
“Arse” is actually even more versatile (whereas its transAtlantic equivalent “ass” is dull in comparison).
In addition to being a noun meaning one’s buttocks, it can also be used as an expletive - “ARSE!” (this was probably instituted by Paul Whitehouse’s character Jed Thomas - or Jed Tucker as he is sometimes billed - in BBC TV’s “The Fast Show” 1994-2001)
and as an intransitive verb meaning “to indulge in horse-play” - “I was just arsing around”.
I don’t think the residents of Ashby would tale kindly to you calling their town a suburb of Leicester. The two places are 18 miles from each other, with a lot of green fields(and the town of Coalville) in between .
There’s also “More arse than class”, achieving something through luck rather than skill, which leads to arsey = lucky. The term famously used by a certain Shane Warne