When to use "России" and when to use "Россия"?

Question

Thanks in advance for any answers or tips.

I am using Duolingo to begin my learning of the Russian language (if there is a better product please let me know). In the beginning lessons they use "Россия" as "Russia" such as "вот Россия". Speaking with a Russian friend and saying "в Россия" was wrong, he corrected it to "в России".

He wasn't sure how to explain the difference and said this: "Может примеры помогут:

1. Россия большая, Россия красивая, Россия интересная
2. Из России с любовью, граница России, экономика России, я еду из России"

Is "Россия" for Russia in general, while "России" is for specific Russian things?

Answer 1

Russian is an inflecting language, like Latin or Ancient Greek. There are six cases for nouns and adjectives.

Nominative: Россия

Genitive: России

Dative: России

Accusative: Россию

Instrumental: Россией

Prepositional: (о) России

(The о in parentheses is a token preposition that it's customary to put there, since the prepositional case is never used without one — hence its name.)

In all of your examples under (2), the case used is genitive. And the fact that three out of the six oblique forms are the same isn't altogether representative. Besides, there's also a plural declension — that would rarely be used with a proper name like Россия, but here goes anyway:

Nominative: России

Genitive: Россий

Dative: Россиям

Accusative: России

Instrumental: Россиями

Prepositional: (о) Россиях

If you're only starting to learn Russian, you'll be introduced to all that eventually. For now, you're getting a little ahead of yourself when you come up with theories of that sort. There's a lot of rules involved in deciding which case to use; most of the time, you can't just chain words together.