"Would you like to go to the coffee morning?"
Translation:Hoffech chi fynd i'r bore coffi?
That would need to be faset ti'n hoffi...? - faset ti here is a form of bod, so the yn/'n is required to make the link to the verb-noun hoffi.
Hoffet/Liciet ti...? is more commonly used than Faset ti'n hoffi/licio...?, though - shorter and easier to say.