Antaŭ ol ni vespermanĝos, mi miksos la salaton kun oleo kaj pipro.

Antaŭ ol means before when it introduces a whole clause.

• antaŭ by itself is usually a preposition meaning before/in front of
• ol is the word that connects it to a clause

So:

• antaŭ la vespermanĝo = before the dinner
• antaŭ ol ni vespermanĝos = before we eat dinner

In Esperanto, antaŭ ol is the normal way to say before + a verb clause.

Yes, native English speakers often first meet ol in comparisons, such as:

• pli granda ol mi = bigger than me

But ol is also used in expressions like antaŭ ol and post ol is not normal, but antaŭ ol is a fixed and very common pattern. In this sentence, you do not need to think of comparison; just learn antaŭ ol as the standard way to say before when a clause follows.

Because vespermanĝi is a normal Esperanto verb meaning to eat supper / to have dinner in the evening.

It is built from:

• vesper- = evening
• manĝ- = eat
• -i = infinitive ending

So:

• vespermanĝi = to dine / to eat supper
• vespermanĝos = will dine / will eat supper

Esperanto often allows this kind of neat word-building. You could also say manĝos vespermanĝon, but vespermanĝos is shorter and very natural.

Because both actions are in the future relative to the moment of speaking.

In English, we often say:

• Before we eat dinner, I will mix the salad.

Even though eat refers to the future, English often uses the present tense after words like before, after, when, and if.

Esperanto does not usually do that. It tends to use the tense that matches the real time of the action.

So if both actions are future, Esperanto commonly says:

• Antaŭ ol ni vespermanĝos, mi miksos la salaton...

That is completely normal.

Because la salaton is the direct object of miksos.

The speaker is doing the action of mixing, and the thing being mixed is the salad.

• mi miksos = I will mix
• la salaton = the salad

In Esperanto, direct objects normally take -n.

Compare:

• Mi manĝas pomon. = I am eating an apple.
• Mi miksos la salaton. = I will mix the salad.

Because they are part of a prepositional phrase with kun.

• kun oleo kaj pipro = with oil and pepper

After a preposition like kun, nouns normally do not take the accusative -n just for being objects of the sentence.

So:

• la salaton gets -n because it is the direct object
• oleo and pipro do not get -n because they come after kun

Because the sentence is talking about oil and pepper in a general sense, not specific previously identified oil and pepper.

So:

• kun oleo kaj pipro = with oil and pepper

This is similar to English, where we often leave out the with ingredients or substances when speaking generally.

If you said kun la oleo kaj la pipro, it would sound more like with the oil and the pepper, meaning some specific oil and specific pepper already known from context.

In normal usage, it means the salad is being mixed with oil and pepper added—basically dressed or seasoned with them.

Esperanto miksi ion kun io often means mix something with something else. Here the most natural interpretation is:

• I will mix the salad, using oil and pepper

So the phrase is idiomatic and natural, even if English might sometimes prefer dress the salad with oil and pepper.

Because the subject changes.

• ni vespermanĝos = we will eat dinner
• mi miksos la salaton = I will mix the salad

So the sentence means that the dinner is something we will do together, but the mixing is something I will do.

This is very straightforward Esperanto clause structure: each clause has its own subject.

Yes. Esperanto word order is fairly flexible, although some orders are more neutral than others.

The given sentence is very natural:

• Antaŭ ol ni vespermanĝos, mi miksos la salaton kun oleo kaj pipro.

You could also say:

• Mi miksos la salaton kun oleo kaj pipro antaŭ ol ni vespermanĝos.

Both mean the same thing. Putting the antaŭ ol clause first gives it a bit of emphasis as the time-setting background.

A comma is very common and helpful there because the sentence begins with a subordinate clause:

• Antaŭ ol ni vespermanĝos, ...

The comma marks the end of that introductory clause and makes the sentence easier to read. In practice, using the comma here is a good habit.

No, not in standard Esperanto for this meaning. The normal expression is antaŭ ol.

So you should learn:

• antaŭ ol mi iros = before I go
• antaŭ ol ni vespermanĝos = before we eat dinner

Using antaŭ ke would not be the standard way to express this.

Yes. That is often the most natural English translation.

Depending on dialect and context, vespermanĝi can correspond to:

• eat supper
• have dinner
• dine

So ni vespermanĝos can be rendered in several natural English ways. The exact English wording may change, but the Esperanto grammar stays the same.