"They were making tasty tea."
Translation:Oni robili smaczną herbatę.
to make tea is a action. why can't this be translated in to oni zaparzyli smaczna herbate?
Because "zaparzyć" is perfective verb, so means not just making tea but finishing making it too – that said, "Oni parzyli smaczną herbatę" should probably be accepted, if it isn't, please report it.
Yes, but "zaparzać" is a different verb than "zaparzyć" that OP used and although you can use it, most Poles perceive frequentative forms of imperfect aspect as highly archaic, so I would debate whether there is any point to mention them in a language course that won't even get you to B2. ;-)
most*. I come from eastern Poland and would hear 'zaparzać' more often than 'parzyć' so I beg to differ. Also 'parzyć' has wider meaning but 'zaparzać' is still vialable verb.
And saying 'my right is the right most mine' (hope you get the reference) is not very Duolingo-like.
*me and maybe my friends or family