Just curious, does 'tha an cat dìleas agam' mean 'I have a loyal cat'?
I think that would be 'Tha cat dìleas agam' as 'an cat' makes it 'the cat'.
Woops, of course, thanks!
I put "Tha mo chat dileas" (which is how Google Translate does it) but had it marked as wrong. I think Duolingo is incorrect. For close relatives, friends, body parts etc "mo" is as good if not better than "an .....agam".
Tha mo chat dìleas will be accepted here, so you must have had a mistake elsewhere in your answer.