В университетском буфете можно купить кефир и йогурт.

In the university snack bar, you can buy kefir and yogurt.

Breakdown of В университетском буфете можно купить кефир и йогурт.

• в: in
• купить: to buy
• и: and
• можно: can

Questions & Answers about В университетском буфете можно купить кефир и йогурт.

Why is it в университетском буфете?

Because в means in / at here, and when Russian uses в to talk about location, the noun normally goes into the prepositional case.

So:

• буфет = buffet, snack bar, cafeteria counter
• в буфете = in the buffet / at the buffet

The adjective has to match the noun:

• университетский буфет = university buffet
• в университетском буфете = in the university buffet

So both words change because they are part of the same prepositional phrase.

What case is университетском буфете, and why do the endings look like that?

It is prepositional singular.

The base form is:

• университетский буфет

After в meaning location, it becomes:

• в университетском буфете

Why the endings?

• masculine/neuter adjective in the prepositional singular often ends in -ом / -ем
• masculine noun буфет becomes буфете

So:

• университетский → университетском
• буфет → буфете

This is just normal adjective-noun agreement in the prepositional case.