"If I were at a party, I would eat cheese cake."
Translation:Taswn i mewn parti byddwn i'n bwyta cacen gaws.
Taswn............Baswn are the usual forms taught, however the written form is usually byddwn. This is also common in some dialects. Most of the sentences in the course use 'taswn.........baswn'
I'm not sure if you meant it like that but your post seems to suggest that you think "Baswn" and "Taswn" are interchangeable which they are not. Also the correct answer for what you suggest i.e using "Baswn" instead of "Byddwn" would be "Taswn i mewn parti, baswni'n bwyta cacen gaws."