Ni atendas en la kafejo ĝis la kunveno finiĝos.

In Esperanto, the simple present tense often covers both the English simple present and present progressive.

So Ni atendas can mean:

• We wait
• We are waiting

The context tells you which sounds natural in English. In this sentence, the idea is clearly ongoing, so we are waiting is the natural translation.

Esperanto can use a more explicitly progressive form, such as Ni estas atendantaj, but that is usually less common and often unnecessary.

En means in or inside, so en la kafejo means the people are physically inside the café.

Ĉe usually means at, by, or at the place of. So ĉe la kafejo would mean something more like at the café or by the café, not necessarily inside it.

So the sentence chooses en because it is talking about being inside the café.

La is the Esperanto definite article, meaning the.

So:

• la kafejo = the café
• la kunveno = the meeting

It is used because the café and the meeting are understood as specific ones in the situation.

Esperanto has no separate word for a/an, so:

• kafejo can mean a café or café in a more general sense
• la kafejo means the café

Ĝis means until or up to the point when.

In this sentence, it marks the time limit of the waiting:

• Ni atendas ... ĝis la kunveno finiĝos
• We are waiting ... until the meeting ends

So the waiting continues up to the moment when the meeting ends.

A useful comparison:

• ĝis = until
• dum = during / while

So ĝis gives an endpoint, while dum describes something happening during a period of time.

This is a very common question.

In Esperanto, verb tenses are normally chosen according to actual time relative to now, not according to the special English rule used after words like until, when, and if.

Since the meeting has not ended yet, its ending is in the future, so Esperanto naturally uses the future tense:

• ĝis la kunveno finiĝos

Literally, this is like until the meeting will end, but that is just how Esperanto works. In natural English, we translate it as until the meeting ends.

So even though English avoids will here, Esperanto normally uses -os.

Finiĝos comes from finiĝi, which means to come to an end or to become finished.

So:

• La kunveno finiĝos = The meeting will end

By contrast, finos comes from fini, which often means to finish something.

For example:

• Li finos la raporton = He will finish the report
• La prezidanto finos la kunvenon = The chairperson will end the meeting

So finiĝos is used because the meeting itself is reaching its end.

The element -iĝ- often adds the idea of becoming or undergoing a change.

No. Atendi can be used with an object, but it does not have to be.

For example:

• Ni atendas la trajnon = We are waiting for the train
• Ni atendas en la kafejo = We are waiting in the café

In the sentence you gave, the important point is not a direct object but the time limit:

• they are waiting
• and they will keep waiting until the meeting ends

So the clause after ĝis tells us how long they are waiting, not what they are waiting for.

These are nice examples of Esperanto word-building.

Kafejo

• kaf- = coffee
• -ej- = place for
• -o = noun ending

So kafejo literally means a place for coffee, which gives café / coffee shop.

Kunveno

• from kunveni = to gather / to meet
• kun- = together
• ven- = come
• -o = noun ending

So kunveno is a meeting, literally something like a coming together.

This kind of word-building is very common in Esperanto and helps a lot with vocabulary.