"What can you do tomorrow?"
Translation:Beth dych chi'n gallu wneud yfory?
I was taught that in a "bod" form, if you have a question word that stands in for the object of the verb (i.e. "you can do IT" --> "WHAT can you do?"), you still have to do the "possessing pronouns around the verb" thing, like we do when a pronoun is the direct object.
You had probably anwered your question before you asked it!
- Beth wyt ti'n gallu ei wneud?
would be a more formal way of writing the sentence, but in the colloquial language the ei is dropped but the mutation it causes is retained.