So, /y/ sounds /i ~ ɨ~ ɪ ~ ə/ and /u/ does the same?
u has no 'schwa' sound. There are links to explanations and examples of pronunciation in these posts - https://www.duolingo.com/comment/13199969
gweiadur.com has real-voice recordings of many individual words.
Both of you could be wrong
Bore da dydd marwth ydy
Oh, come on, give us a bit more of a challenge than that! Only options are 'dydd' and 'Sul' This isn't the first lesson on days of the week. Please increase the difficulty a little bit.
I thought this is meant to be lesson 4 of the days of the week, not lesson 1!!