I would imagine it's difficult enough teaching English in ANY American school!

I say this because about 60% of white Americans I've met had problems getting my surname right (variations from Aitchison to Wilkinson)! How they'd cope if it was Cholmondeleigh-Featherstonehaugh I really cannot imagine!

All of which is to say that there is no such thing as 'standard' English -even in England! Neither you nor your students, if faced with a full-on Geordie, would understand a word they said! This in spite of a near fifty-year campaign by the BBC and the education system to impose 'Received Pronunciation' on the UK!

The only real problem arises in the cases of specialised and restrictive technical jargons - geek-speak - and vocabularies. People acquire these as they go along, if they need them. For the rest, as long as communication is possible, there's no point wasting time and effort.

People will fidn ways to understandceach other and work together as and when they need to. Or to put it another way, Darmok and Jalad at Tanagra.