jIH:

1) jaghpu'na'ma' chaH qama' 'ar'e' ?
or
2) jaghpu'na'ma' chaH qama''e' 'ar ?

I rethought this matter and decided that unless there is any Ca'Non
which suggests otherwise, to be placing the {-'e'} on the noun instead
of the question word {'ar}.

So, in the example above I'd finally choose to write {jaghpu'na'ma'
chaH qama''e' 'ar ?}.

First of all, there's something which seems wrong with writing
{jaghpu'na'ma' chaH qama' 'ar'e' ?}.

And second, the only question words in Ca'Non known to be able to bear
type-5 suffixes are the {'Iv} and {nuq}, since they occupy *exactly*
the same position as their answer. But (as far as I know), there is
nowhere written that the {'ar} functions similarly.

nuqDaq also occupies the same location as the answer, but it's said to be a combination of nuq + -Daq, so it's already got a type 5 suffix and can't have another.

Lacking any instructions whatsoever on the mutual use of 'ar and type 5 suffixes, I too would not assume the suffix goes on 'ar. And this isn't limited to translations of "to be" sentences.

How many buildings do you work in?
qachDaq 'ar bIvum?

But if we do receive word later that the suffix migrates to the 'ar, I will not be surprised or dismayed.

-- 
SuStel
http://trimboli.name