Questions & Answers about Вечером мы идём в театр на новый спектакль.
Why is it вечером and not вечер or вечера?
Вечером is the instrumental case of вечер and is the standard way to say “in the evening / this evening” in Russian.
- вечер – nominative, “evening” (as a subject: Вечер холодный – The evening is cold).
- вечером – instrumental, used for general time expressions:
- Утром – in the morning
- Днём – in the daytime
- Вечером – in the evening
- Ночью – at night
So Вечером мы идём... literally feels like “(During the) evening, we are going…”. Using вечер or вечера here would be ungrammatical in this meaning.
Why is the present tense идём used to talk about the future plan?
In Russian, the present tense of a verb of motion can express a near future arrangement, especially with a time expression:
- Вечером мы идём в театр. – We’re going to the theater this evening.
- Завтра я лечу в Москву. – I’m flying to Moscow tomorrow.
This is similar to English present continuous (We are going…), but in Russian you just use the simple present. The time word (вечером) clarifies that it’s about the future, not about a habit.