"Morgan do you like coffee?"

Translation: Morgan, dych chi'n hoffi coffi?

[Alkimeer]

Do both 'wyt ti'n' and 'dych chi'n' mean the same thing? Any differences?

[EllisVaughan]

Wyt ti is informal. Think Tu in french and Du in german. Dych chi is fromal. Think Vous in french and Sie in german.