Should there be a comma before Megan since she's being addressed, or are clauses separated differently in Welsh?
No, it's the same as English. Depends how "correct" you want your punctuation to be.
So they should add one in the lesson. Hey, does your name "shwmae" mean "hi" in Welsh?
It is: pryd (time) + nawn (noon).
Pryd is a common word, and as well as meaning "time" it can mean "when?".
Nawn isn't used today but it's a cognate with English "noon", both from Latin "nōna (hōra)" (ninth hour) i.e. 3 o'clock in the afternoon.
PS I've seen your helpful comments on the Hebrew course. Diolch / תודה!
The hint showed when you click on the word is not clear. I wondered the same.
If someone wanted to exclude the "good" from "good afternoon," to a Welsh person, how would it sound to be told "Prynhawn, <name>."
Without the "da," does this make it incorrect or simply informal?
You wouldn't drop the da as Prynhawn, Siân sounds like you're saying "Siân's afternoon". If you want to make it more informal, you can shorten it to P'nawn da, Siân.
So is the stress on the first syllable MEgan, but on the last syllable for DyLAN?
Thank you! So does that mean that the 'y' in 'Dylan' is pronounced like a schwa still, because it is not in the last syllable?