Breakdown of Между лекциями мы заходим в буфет и берём по чашке чая, но сегодня в буфете не было кефира.
Questions & Answers about Между лекциями мы заходим в буфет и берём по чашке чая, но сегодня в буфете не было кефира.
Because между normally takes the instrumental case when it means between.
- лекции = lectures
- instrumental plural = лекциями
So между лекциями literally means between lectures. This is a very common time expression in Russian.
This is the usual Russian contrast between motion toward a place and location in a place:
- в буфет = to the cafeteria/snack bar → movement, so Russian uses the accusative
- в буфете = in the cafeteria/snack bar → location, so Russian uses the prepositional
With masculine inanimate nouns like буфет, the accusative singular looks the same as the nominative, so you see буфет with no ending change.