"What did you think about?"
Translation:Про що ви думали?
I have had the same issues with P and R. I wonder if Duolingo wants some other letter such as in х equating to kh?? Also if you have Windows 10 you can add a second language to the keyboard and easily switch with windows key and the keyboard. Ukrainian stickers are all over ebay and Amazon.
the answer is past tense, думали. an ли ending indicates groups of people or you. I am assuming this is so because sometimes you could be a group of people. As for the hints, they are not always accurate. Most of the time they are useful, but I find if the hint tells me something different than I think the answer is, I go with the answer I think I should put down; I'm usually correct.