If dónde translates to where or how, I tend to write "how are you today" because it makes much more sense to me. Why is it marked wrong?
"Donde" is always "where," in my experience, and "como" is "how." I am not sure how or why Duo has done this, but I'd stick with "where" from now on, IMO. My dictionary does not list "how" as an option for "donde."
Hmm that's weird. It was the first on my dictionary list when i viewed it, but I'll always stick with "where" from now on, too. Thank you!
Why is "Where do you stay today?" a wrong translation?
Because "estas" translates directly to "you are", or as here "are you" because it is a question. There is no Spanish word for stay in the phrase.
Donde estas hoy actually translates to where are you now.