Suggested Ga i dalu? Cewch as an alternative.
Do Welsh people always answer their own questions? It doesn't seem to happen so much in other languages in Duolingo.
That's just a thing we do. We do it regardless of the language we're speaking.
T mutated to d here because of ga i...?
Yes. talu is the object of the verb ga i....? and so it gets a soft mutation.