Learn Russian: Вот бы эта бесконечная зима вмиг закончилась! - If only this endless winter would end instantly!

The particle вот бы triggers the subjunctive mood to express an unrealized wish. In Russian, this requires using either the past tense or an infinitive. Because we have a clear subject performing the action (эта бесконечная зима), we use the past tense, which changes to match the gender and number of that subject.

Why do we use the perfective verb закончилась here instead of the imperfective?

The speaker is wishing for a single, completed result: the definitive end of the winter. If we used the imperfective заканчивалась, it would focus on the gradual process of ending, which directly contradicts the speaker's desire for it to happen вмиг (instantly).

Is the adverb вмиг related to the word миг?

Yes! The noun миг means a brief moment or an instant. By combining it with the preposition в, Russian forms the adverb вмиг, which means in a moment, instantly, or in a flash.

Why does the verb have the reflexive -лась ending here?

The non-reflexive verb закончить is transitive, meaning someone finishes a direct object (like finishing a project or a meal). Because the winter isn't finishing something else, but rather coming to an end on its own, we must use the intransitive reflexive verb закончиться.