Se la kelnerino ankoraŭ ne alportos la menuon je la sepa, ni mendos nur supon kaj salaton.

That is a very common question.

In Esperanto, it is normal to use the tense that matches the actual time of the action, even inside a se clause. Since the bringing of the menu is still in the future, alportos is future.

So:

• Se ... alportos ... ni mendos ... = If ... will bring / has brought by then ... we will order ...
• More natural English uses present or present perfect after if, but Esperanto does not have to copy that pattern.

So the sentence is structurally normal Esperanto:

• Se la kelnerino ankoraŭ ne alportos ...
• ni mendos ...

Both actions are future, so both verbs are future.

Esperanto does not have a special tense exactly like the English present perfect.

Instead, it often combines:

• a normal tense form
• with words like ankoraŭ = still / yet
• and a time expression

So ankoraŭ ne alportos here means something like:

• still won’t have brought
• or more naturally in English, still hasn’t brought yet at that future time

The important idea is that at the moment being discussed, the action is still unfinished.

So in context:

• Se la kelnerino ankoraŭ ne alportos la menuon je la sepa... = If by/at seven the waitress still hasn’t brought the menu...

Here je la sepa means at seven o’clock.

Esperanto often tells time with:

• je la unua = at one
• je la dua = at two
• je la sepa = at seven

Literally, this comes from an omitted noun:

• je la sepa horo = at the seventh hour

Usually horo is simply left out.

Because clock time is commonly expressed with an ordinal form, not just the plain number.

• sep = seven
• sepa = seventh

So je la sepa literally means at the seventh [hour].

That is why Esperanto uses sepa, not sep, in this kind of time expression.

Literally, je la sepa means at seven.

In this sentence, it sets the moment when we check the situation:

• If at seven the waitress still hasn’t brought the menu, we’ll order only soup and salad.

If you wanted to stress a deadline more explicitly, ĝis la sepa could mean by seven.

So:

• je la sepa = at seven
• ĝis la sepa = by seven / up to seven

Kelnerino means waitress.

It is built from:

• kelnero = waiter / server
• -in- = female
• -o = noun ending

So:

• kelnero = waiter
• kelnerino = waitress

The -in- suffix is a very common Esperanto way to mark female persons.

They take -n because they are direct objects.

In Esperanto, the direct object usually gets the accusative ending -n.

Here:

• alportos la menuon = will bring the menu
• mendos supon kaj salaton = will order soup and salad

So:

• menuo → menuon
• supo → supon
• salato → salaton

The -n marks what is being brought or ordered.

Because the sentence is talking about some soup and salad, not specific soup and specific salad already identified.

Esperanto uses la only for definite nouns, roughly like the in English.

So:

• la menuon = the menu
  (a specific menu the waitress is expected to bring)

but:

• supon kaj salaton = soup and salad / some soup and salad
  (not previously identified, just the kinds of food they will order)

Nur means only.

In this sentence, it limits what they will order:

• ni mendos nur supon kaj salaton = we will order only soup and salad

So the idea is:

• not the full meal
• not something else
• just soup and salad

With nur, position matters somewhat, but here its meaning is very clear: it applies to the whole object phrase supon kaj salaton.

Yes, Esperanto word order is fairly flexible, but different positions can slightly change emphasis.

For example:

• Se la kelnerino ankoraŭ ne alportos la menuon...
• Se la kelnerino ne ankoraŭ alportos... → this sounds awkward
• Ni mendos nur supon kaj salaton.
• Ni nur mendos supon kaj salaton. → can suggest we will only order rather than do something else

So the original sentence has a natural, clear word order.

Especially:

• ankoraŭ ne is a very common pair meaning not yet
• nur is naturally placed right before what it limits

Yes, it is normal and recommended.

The first part is a subordinate conditional clause:

• Se la kelnerino ankoraŭ ne alportos la menuon je la sepa

Then the main clause follows:

• ni mendos nur supon kaj salaton

A comma between them makes the structure clear, just as in English:

• If ..., we will ...

So the punctuation here is standard.