"Do you like listening to music?"
Translation:Dych chi'n hoffi gwrando ar gerddoriaeth?
Maybe a long time a go soft mutation could be explained as occuring due to a vowel, however that is no longer the case. Many words that end with consonants cause soft mutation, with "ar" being one of them. Twelve main prepositions cause soft mutation, "Am, Ar, At, Dan, Dros, Drwy, Heb, I , O, Gan, Wrth, Hyd".
As shwmae says, above: 'dych chi' is for 'you' when it's someone you don't know very well, or whom you want to place above you heirarchically, or distance yourself from.
'Dych chi' is ALSO used if you're talking to more than one person, however well you know them or what you think of them! eg one police officer; one older person; two children; two of your friends.
So that leaves 'wyt ti' for one person whom you know well, or who you don't need to avoid offending (I hope we'd all respect everyone, after all, whoever they are and however old or young they are!). I'm a learner, but I read that people say 'wyt ti' is for eg talking to one child.
Translating from Welsh in to english we only have 'you' to choose from nowadays! 'Thee' and 'thou' are no longer in current use.