Ещё чая или ещё чаю
I got confused with what I should use after ещё , dative or genetive ??? And I have read a stentence (Ещё кружку чая =another mug of tea) Is it true or not.... and if it's true why we use accusative here
I don't think чашку чаю sounds bad. I'd say it actually sounds too good to be used :)
It sounds like noblemen would say in the late 19th century. But now since we've first either killed or chased away all our noblemen and then uprooted their cultural heritage that tried to survive in (some part of) the soviet-era clerisy, it does sound unusual and too refined, as if the person who says it has spent the last 100 years locked in a bookcase. Or is playing one who has ;)
But it doesn't sound bad, just a little bit dusty. Honestly, this is one of those bits of the old-school language I'd love to hear more often.