Another weird and wrong past tense in English
I think they are going for the literal translation to highlight how is said in Welsh.
But I've also heard that the sentences sound odd or even wrong in Welsh as well.
In this discussion someone alleges you can only use wedi with periods of time still occuring, that it is incorrect Welsh to be used this way... https://www.duolingo.com/comment/13254290
Yes, dach chi or dych chi are both possible - depending on where in Wales you are, you may hear one or the other.
Wyt ti? This is new can someone please explain this?
In German terms, wyt ti ...? is bist du ...? or ...st du? while dych chi ...? is seid ihr ...? sind Sie ...? or ... ihr? ...en Sie?.
That is, wyt ti is singular/informal and dych chi is plural and/or formal.