Why does the guide to gwers3 include I Fynwy and pay when they do not appear in the dialogue? Also why does the word for desire not appear in the guide (nor in my dictionary!)

Possibly, a mistake. As to the word “desire” I believe the word used is “Chwant or Awydd” …

S’mae Neville,

I assume that you are referring to Northern course 2? These guides were collated by people from the forum, and they may have made mistakes as Kim said.The Northern word used for “eagerness” is awydd; which dictionary are you using? Awydd, awyddu and awyddus are all in Y Geiriadur Mawr.