Proper. It is a name of a city in Russia.
Yes, the word 'Moscow' is a noun, a proper noun, the name of a specific place.
As a name of a road , Park Avenue', it is a proper noun, and both words star with a capital letter. However, when used separately, as 'the park, or 'the avenue', they are common nouns and so not need a capital letter.
No. Moscow is the fifth most populous city in the world, by city proper. It is, however, the largest city in Europe.
proper
common
common and proper
As part of the city political limits or proper, yes. But the greater metropolitan area of Mexico City is much bigger:Population (city proper, 2015):Moscow: 12.2 millionMexico City: 8.9 millionPopulation (greater metropolitan area, 2015):Moscow: 16.8 millionMexico City: 21.2 million
It is a proper noun, because it is the name of a specific thing.
common
it's a common noun. a proper noun would be Spider-Man.
All are their nation's Capital.
Proper