"I want seventy three apples."

Translation: Dw i eisiau saith deg tri afal.

[Lundgren8]

Does tri not cause aspirate mutation? I wrote hafal. Same goes for the sentence pedwar deg chwech afal. Or is it only with t p c? From page 6 here: http://www.bbc.co.uk/wales/learnwelsh/pdf/welshgrammar_mutations.pdf

[ibisc]

tri causes aspirate mutation of p, t, c, but does not add not h to vowels.

[Lundgren8]

Thanks, perfect answer!

[EllisVaughan]

The addition of "h" only happens after a select few words, and it considered a part of the other mutations as they all affect a single letter, whereas the "h" is sometimes added to the front of a word beginning with a vowel.