Learn Russian: Вы когда-нибудь были в нашем городе?

The word когда means "when," and the suffix -нибудь adds the idea of "any" or "some." So когда-нибудь literally translates to "at any time." In questions about life experiences, it is the standard Russian way to say "ever."

Why does the English translation say "Have you ever been" but the Russian just uses the past tense были?

Russian doesn't have a separate grammar structure for "have done" or "have been" (the present perfect tense). To ask if someone has ever experienced something, Russian simply pairs the standard past tense (были) with a word like когда-нибудь.

Why does the Russian sentence say в нашем городе (in our city) when the English says "been to"?

In English, we say we have "been to" a destination. In Russian, the verb быть (to be) always describes a static location, not a movement towards something. Because you are located in the city, you must use в (in) rather than a preposition meaning "to."

Why did наш город (our city) change to нашем городе?

Because the sentence describes a location using the preposition в (in), the words following it must be in the prepositional case. The noun город gets an -е at the end, and the masculine word наш changes to its prepositional form, нашем.