I wouldnàt say itàs colloquial, perhaps more a case of formal (Aunt) and informal (Auntie or Aunty). But I garee both are correct English and I would support the suggestion that DL find a moment to change the database to accept either. The more I use DL the more I come round to the view that good translation should include 'common usage' as well as what would be considred grammatically correct. Perhaps this reflects the differences between written and spoken language.
I don't understand what range of "typos" duolingo accepts. Half the time when I get a wrong answer its beacuse of a typo, usually from one letter being right next to the one I needed. I accidentally typed "sia" instead of "zia" and i got it wrong. after an hour of doing my lessons it gets really aggravating to constantly get wrong answers because of one letter mistake,
Duolingo could you please learn to recognise countries outside of the USA. It's tiresome to be always told an answer is wrong just because I (we) don't know the American form of something. Perhaps if you fix mistakes (for example those reported three years ago!) we wouldn't clutter up the comments section with our grievances. Surely you have a team to fix these things!