"Aunt An eats papaya."
Translation:Dì An ăn đu đủ.
I think they did this because Vietnamese family trees are so large and it's difficult to learn all of the correct names for your relatives. They thought "Dì" was the most simple way to go, probably. I do think that people should know all of the variations for "aunt", though.
In the Notes to Basics 1, it says 'Due to the almost unlimited combinations of pronouns, we cannot add them all to the database. Therefore, do not try to enter different pronouns other than those above or your answer will be marked wrong.' They are probably doing the same with words like aunt.
Sure, thanks. It seems to suggest that "an" is pronounced like "Ann" whereas "ăn" is more like "arn". However, Google Translate to my ear pretty much does the same "ar" sound with different tones for the two. The pronunciations given by Duo are also practically the same! So I wonder... Anyway, I'll content myself with them being practically identical until I, if ever, become a fluent Vietnamese speaker then.