Yn Gymraeg possessive pronouns cause different mutations to each other.
Edrychwch ar y brawddegau hyn:
Ei gath e.
cathgath
Ei chath hi.
cathchath
Ein cath ni.
dim treiglad
Ein cath ni.
dim treiglad
In formal Welsh you will see 'ei gath' and 'ei chath' rather than 'ei gath e' and 'ei chath hi'. We tend to add the 'e', 'hi', 'ni', and 'nhw' when talking.
'Ei' is used when talking about males and females. Therefore, we must remember to use the correct mutation or the meaning of the phrase could be wrong.