Breakdown of Этот глобус показывает координаты как города Москвы, так и острова Сахалин.
и
and
город
city
этот
this [f: эта, n: это]
показывать
to show
Questions & Answers about Этот глобус показывает координаты как города Москвы, так и острова Сахалин.
Why is Moscow in the genitive case (Москвы) but Sakhalin stays in the nominative (Сахалин)?
This is a key rule for geographical appositives in Russian! When a well-known city or river is paired with a generic word like город (city), the proper name usually agrees in case. Since города is genitive here, Москва becomes Москвы. However, names of islands (остров), lakes, mountains, and stations typically do not agree and remain in the nominative. That is why we say острова Сахалин.
Could I just drop the generic words and say координаты Москвы and координаты Сахалина?
Yes, absolutely. Dropping the generic words города and острова is very common. Notice, however, that if you drop the word острова, the island name is no longer shielded by the generic noun and must take the genitive case on its own to show possession, becoming Сахалина.
Why are the generic words города and острова in the genitive case to begin with?
They are in the genitive case to link them to the noun координаты. Just like in English where we say 'coordinates of the city' and 'of the island', Russian uses the genitive case to show this 'of' relationship.
How does the как ..., так и ... structure work here?