From Wiktionary, the free dictionary
da iawn (feminine singular da iawn, plural da iawn, not comparable)
- very good
Roedd y ffilm 'na'n dda iawn.- That film was very good.
da iawn
- well done
Wnest ti dacluso dy stafell di? Da iawn!- Did you clean your room? Well done!
Note: Certain mutated forms of some words can never occur in standard Welsh.
All possible mutated forms are displayed for convenience.