I don't speak Welsh but I think it's: Diolch i chi fy ffrind.
You can check it with free translation services on the Web.
"Thank you" in Welsh is "diolch."
The Welsh word for friend is ffrind.The Welsh word for best friend is ffrind gorau.ANOTHER ANSWER:fy ffrind or fy nghyfaill. (my friend).
ddiolch 'ch' m chyfaill
Diolch i ti ffrind
Diolch am bobeth!
You can say "diolch yn fawr iawn" in Welsh to express "thank you very much".
cyfaill
Thank you = Obrigado
Ffrind gorau
diolch yn fawr iawn!
Fy ffrind trydedd
Diolch am eich dymuniadau da.