"Yes, I have earache."
Translation:Oes, mae clust dost gen i.
If you look at the 'Hints and Tips' for this section you will notice that most generalised infections (colds, flu, a temperature, chicken pox, malaria, ...) are ar someone, whereas more local problems with particular parts of the body (broken arm, bruised head, earache) are gyda/gan someone.
Sorry, I thought I read the 'Hints and Tips' before refreshing the unit. Apparently not enough.
I did add a sentence to the notes to highlight ar vs gyda - that might have been after you went over the notes. We try to update the notes from time to time in response to common discussion points.