What do you mean by borough? A city?

Screw off Norman and stop trying to make our Anglish your Franglish!

Borough, a big town, a burgh.

Ahah I was sure of this , trying to not use 'bastard' words right? Well guess what, city is an English term not a French one (we use "ville" in French cité is not used for cities, unlike Spanish or English, cité is only used for medieval town or with fortifications such as 'la cité de Carcassonne'), like it or not English has plenty of words of latin origin. As for borough or burgh, again in French we have the same word "bourg" for it used for middle sized towns, like 'le bourg péage' or 'bourg en Gironde'. Many French cities has 'bourg' in their name such as Cherbourg or Bourgoin Jallieu and as for this last town the 'bourg-' part has even not any german origin but gaulish (see berg).

So if you are talking about a big city use proper English with the word city : the term may be used either for a town possessing city status; for an urban locality exceeding an arbitrary population size; for a town dominating other towns with particular regional economic or administrative significance. I hope to have helped you here.

Yes, but it comes from Latin, it does not belong in English (especially since it doesn't even keep the meaning right). And this is not an English-only problem, although other tongues' problems with this are relatively tiny. Bourg does not belong in French - nor does attacher, developer, chlinguer and a few other words - these are Germanic or Celtic words.

I mean borough, or burgh.

Ok well never mind, was just pointing out that burgh, bourg, burgo, berg and any variants are not necessarily a term of German or English origin since it is found in most of the indoeuropean languages even in Persian and Sanskrit.

Does this 'borough' or 'city' has any status of capital (regional, local, national, historical)?

Yes, but it gets harder to trace without writing, but as long as there is no real proof of borrowing words, then it's ok with me.

It is national capital.

3.5

Is any Slavic language an official one in it?

No, though it has a 5% Russian ethnic population.

Is in in a country with a name in English that ends in "stan"?

No.

1.5