Not really. Usually:
- Thala i ddim - 'I will not pay'
dim byd - 'nothing'
Thala i ddim byd - 'I will not pay anything', 'I will pay nothing'
- Thala i ddim byd o gwbl - 'I will not pay anything at all', 'I will pay nothing at all'
I do not know why Duo is not using the usual mixed mutation in negative verbs (aspirate mutation of p, t, c, soft mutation of b, d, g, m, ll, rh). Although the aspirate mutation is gradually falling out of favour in the colloquial language, it is still there at the moment.