The treiglad trwynol or nasal mutation is one of those letter changes at the beginnings of words. The letters affected are: ptc, bdg. The two main causes of this treiglad are that the word comes after 'yn', which means 'in' somewhere, or that the word comes after 'fy' which means 'my' something.

Examples using p, t, c

Examples using b, d, g