Many pronouns cause mutations.
Rhagenwau (Pronouns) + Treigladau (Mutations)
Welsh pronouns are followed by the following mutations:
| Mutation | ||
| fy | nasal | cerdd > fy ngherdd i |
| dy | soft | barn > dy farn di |
| ei (m) | soft | drama > ei ddrama e/o |
| ei (f) | aspirate | tro > ei thro hi |
| ein | - | barn > ein barn ni |
| eich | - | cerdd > eich cerdd chi |
| eu | - | drama > eu drama nhw |
NB
The aspirate h is placed in front of a vowel at the beginning of nouns and verb-nouns after ei or 'i (fem.), ein or 'n and eu or 'u, e.g.
ei hysgol hi
ein harwain ni.