"Dw i'n gwrando ar y radio."

Translation: I am listening to the radio.

[evallen37]

What is the difference between "ar y" (ar y radio) and "i'r" (i'r parti)?

[rmcode]

The proposition 'ar' generally means on, the literal translation of 'gwrando ar' is 'to listen on', when that is transposed to English it becomes 'to listen to'

The preposition 'i' is used to indicate movement 'to', so 'mynd i'r parti' = 'to go to the party'