I think I’m getting confused over tenses.
Intermediate, vocabulary supplement 7, at 17:36, Is the dog out back?
My reply: Oor key un uh kevin?
The reply given: Ideer key un uh kevin?
I would have translated this as: Was the dog out back - this would be consistent with my last question around “has someone…” or “ydy rhywun wedi…” (at 16:18)
You were exactly right, David. Both forms are perfeclty good in speech (in fact the “ydy” form is what you would use in literary Welsh every time). I may be a bit guilty of mixing forms in the C2 vocab units, but you know I’ll make some kind of claim about making you more flexible speakers / understanders…
In a bit more depth, the full form is “A ydyw’r ci…”, and the “ydyw” get’s shortened different ways by different speakers (and the A disappears completely)
Iestyn ap Dafydd wrote: but you know I’ll make some kind of claim about making you more flexible speakers / understanders…
Was this the same kind of idea you had when you threw in the word “angen” instead of “eisiau” in lesson 5 of course 3 (at 08:28)??!! 
Aagh! No that was pure inefficiency…
Diolch yn fower.
Onward…