"They will go to the bank to fetch money after they play rugby."

Translation: Ân nhw i'r banc i nôl arian ar ôl iddyn nhw chwarae rygbi.

[JamesTWils]

What is this iddyn form?

[areddragon]

The Must & Must Not section explains this quite well. Certain prepositions changes depending on the following pronoun, including i and ar.

• I fi - To me
• I ti - To you (fam)
• I chi - To you
• Iddi hi - To her
• Iddo fe - To his
• I ni - To us
• Iddyn nhw - To them

[JamesTWils]

Thank you. I should have remembered this, but I was thinking of a verb.