После занятия мы идём в буфет и берём по чашке чая.

Because после always takes the genitive case.

The noun занятие is neuter singular. Its genitive singular form is занятия.

So:

• занятие = a class / lesson / session
• после занятия = after the class / after class

This is a very common pattern:

• после урока = after the lesson
• после лекции = after the lecture
• после работы = after work

Занятие is a broad word. Depending on context, it can mean:

• class
• lesson
• session

In this sentence it is singular because the idea is after one class / after the class.

If you said после занятий, that would usually mean after classes or after lessons, often referring to the end of the school day or after a set of classes.

So the difference is roughly:

• после занятия = after the class / after one lesson
• после занятий = after classes

This is a very common learner question.

• идти / идём is used for movement in one specific direction, or for a concrete trip
• ходить / ходим is used for repeated, habitual, or back-and-forth movement

In this sentence, Russian presents the action as a concrete next step: after class, we go to the cafeteria and take tea.

So идём sounds natural because it describes a specific movement from one place to another.

That said, ходим could appear in a different context if you wanted to stress a repeated habit:

• После занятия мы обычно ходим в буфет.
  = After class we usually go to the cafeteria.

So:

• идём = we go / we’re going there
• ходим = we go there regularly / as a habit

Originally, yes: идти is the verb for going on foot.

But in many everyday situations, especially inside a building or over a short distance, Russian uses идти very naturally even when English would simply say go.

So here you should not over-interpret it. It just means they move to the cafeteria.

Because Russian distinguishes destination from location:

• в + accusative = into / to
• в + prepositional = in / inside

Here the cafeteria is the destination, so Russian uses в буфет.

Compare:

• Мы идём в буфет. = We are going to the cafeteria.
• Мы сидим в буфете. = We are sitting in the cafeteria.

Also, буфет is an inanimate masculine noun, and its accusative singular looks the same as the nominative singular, so you see буфет in both forms.

In Russian, буфет often means a snack bar, cafeteria counter, or canteen-like place, especially in a school, university, theater, or workplace.

It does not always mean a large self-service buffet in the English sense.

So in this sentence, буфет is probably the place where students can buy drinks and snacks.

Here по means each, apiece, or one each.

So:

• берём по чашке чая = we each take a cup of tea

This is called a distributive use of по: the same amount is distributed to each person.

Very common examples:

• по яблоку = one apple each
• по билету = one ticket each
• по чашке кофе = a cup of coffee each

Without по, берём чашку чая would usually sound like we take a cup of tea, which could suggest just one cup total, not one for each person.

Because after distributive по, Russian often uses the dative singular.

So:

• чашка = nominative
• чашке = dative singular

That is why you get:

• по чашке
• по книге
• по яблоку

This is one of those patterns that learners mostly need to memorize:

• по + dative singular often means one each

Because чашка чая means a cup of tea, and Russian normally puts the substance in the genitive after a container or quantity word.

So:

• чашка чая = a cup of tea
• стакан воды = a glass of water
• бутылка молока = a bottle of milk

Here:

• чашке = cup
• чая = of tea

So the structure is:

• по чашке чая = a cup of tea each

It can be understood either way depending on context, but most likely it is a routine or a typical sequence.

Russian present tense often works like English present tense in sentences about habits:

• После занятия мы идём в буфет...
  = After class we go to the cafeteria...

It can also sound vivid and immediate, as if the speaker is walking you through what happens next.

So the present tense here is completely natural.

Yes. Russian often omits subject pronouns when the verb ending already makes the subject clear.

Since идём and берём clearly show we, you could say:

• После занятия идём в буфет и берём по чашке чая.

That sounds natural too.

Including мы can make the subject a little more explicit, or help with contrast:

• Мы идём в буфет, а они домой.
  = We are going to the cafeteria, and they are going home.

No, Russian word order is fairly flexible, but the version given is a very natural neutral order.

• После занятия мы идём в буфет и берём по чашке чая.

This presents the information clearly and smoothly.

You could also hear:

• После занятия идём в буфет и берём по чашке чая.
• Мы после занятия идём в буфет и берём по чашке чая.

These are all understandable, but the word order may slightly change what feels emphasized or what sounds most natural in a particular context.

Ё represents the sound yo, and it is always stressed.

So:

• идём is pronounced roughly idyom
• берём is pronounced roughly beryom

In everyday Russian writing, people often replace ё with е, so you may also see:

• идем
• берем

But the pronunciation is still идём, берём.

Learner materials often keep ё because it helps with pronunciation and stress.