Now, on the other hand, if the question is:
{nagh 'oH'a' Dochvam'e'?}

then answering with {'oH.} or {'oHbe'.} makes perfect sense.

I wouldn't say that either. 'oH does not mean be or is. It just means it. We use it to translate English "to be" sentences, but there's still no be in there. Tarzan jIH; Jane SoH Me Tarzan; you Jane.

We add verb suffixes to the pronoun because copula relationships can be continuous or negated or queried and so on, but it's still a pronoun, not a verb.

And if you strip away the linking of the pronoun with some noun, you have no copula left. Saying 'oH is not saying it is (something general or unspecified); it is only saying it.

If you must give a full answer to nagh 'oH'a' Dochvam'e', it would be nagh 'oH. It can't get any smaller.

-- 
SuStel
http://trimboli.name