British English spelling not currently accepted
I think Duolingo should accept British English spelling in translations. When English is not the target language, there should not be a preference.
It would be really nice if there was an option for dialects e.g. I say I'm English, British and it shows a British interface (possibly rejecting American translations, or providing a note pointing out that it isn't how a British person would say it)
also you could choose dialects for the languages you're learning Spanish (Spain or Mexico), Portugesue (Portugal, Brazil) etc.
They could use simple formulas e.g soccer>football, football>American football, color>colour; for abmiguous words (learned>learnt or with no change depending on context) they could allow any dialect