Se la vetero restos bela, ni promenos laŭ la strando kaj aŭskultos la maron vespere.

Se means if. It introduces a condition:

• Se la vetero restos bela = If the weather stays nice

This is the normal way to begin an if clause in Esperanto.

Resti means to remain or to stay.

So:

• la vetero estos bela = the weather will be nice
• la vetero restos bela = the weather will stay/remain nice

Using restos suggests that the weather is already nice now, and the speaker means if it continues to be nice.

The ending -os marks the future tense in Esperanto.

Here all three actions refer to the future:

• restos = will remain
• promenos = will walk
• aŭskultos = will listen

Esperanto often uses the future tense in both parts of a real future condition:

• Se la vetero restos bela, ni promenos...
• If the weather stays nice, we will walk...

That is more direct than English, which often uses present tense after if: If the weather stays nice, we will walk...

Estus is the conditional form, meaning would be.

That would usually suggest something more hypothetical or unreal:

• Se la vetero estus bela, ni promenus... = If the weather were nice, we would walk...

But the original sentence is about a real possible future situation, so Esperanto uses the future tense:

• Se la vetero restos bela, ni promenos...

In Esperanto, la is the definite article, meaning the.

La vetero means the weather. In practice, Esperanto often uses la with things that are understood as specific in context, including general conditions like the weather.

So la vetero is the normal way to say the weather.

Adjectives in Esperanto agree with the noun they describe.

• vetero = weather, singular
• bela = beautiful / nice, singular adjective form

If the noun were plural, the adjective would also be plural:

• belaj tagoj = beautiful days

But here vetero is singular, so bela stays singular too.

Laŭ means along, according to, or sometimes in accordance with, depending on context.

In this sentence it clearly means along:

• promenos laŭ la strando = will walk along the beach

So it describes movement following the line of the beach.

Normally, prepositions in Esperanto are followed by the basic noun form, not the -n ending.

So:

• laŭ la strando = along the beach

The -n ending is used for direct objects, and sometimes for direction, but after a preposition you usually do not add -n unless there is a special reason.

Here laŭ already gives the idea clearly, so la strando is correct.

Because la maron is the direct object of aŭskultos.

• aŭskulti = to listen to
• aŭskultos la maron = will listen to the sea

In Esperanto, direct objects take -n.

So:

• la maro = the sea
• la maron = the sea, as the object

This is different from English, where listen normally needs to. Esperanto uses aŭskulti directly with an object.

Because aŭskulti is a transitive verb in Esperanto. It takes a direct object directly.

So Esperanto says:

• aŭskulti la maron

not:

• aŭskulti al la maro

That is a very common thing for English speakers to notice, because English requires listen to.

Vespere means in the evening or during the evening.

It is an adverb formed from vespero (evening) by using the adverb ending -e.

So:

• vespero = evening
• vespere = in the evening / evenings / during the evening

Esperanto often uses this adverb style for times of day:

• matene = in the morning
• tage = during the day
• nokte = at night
• vespere = in the evening

You could say en la vespero in some contexts, but vespere is more natural here.

The comma separates the if-clause from the main clause:

• Se la vetero restos bela, ni promenos...

This is similar to English punctuation:

• If the weather stays nice, we will walk...

It helps show where the condition ends and the main statement begins.

Yes. Esperanto allows that easily.

For example:

• Ni promenos laŭ la strando kaj aŭskultos la maron vespere, se la vetero restos bela.

This means the same thing:

• We will walk along the beach and listen to the sea in the evening, if the weather stays nice.

The original version starts with the condition first, which is very common.

Because the same subject, ni (we), applies to both verbs:

• ni promenos
• (ni) aŭskultos

Esperanto often leaves the subject unstated the second time when it is the same and the meaning is clear.

So:

• ni promenos laŭ la strando kaj aŭskultos la maron = we will walk along the beach and listen to the sea

This is just like English.

They refer to two different things:

• la strando = the beach, the shore where people walk
• la maro = the sea

So:

• promeni laŭ la strando = to walk along the beach
• aŭskulti la maron = to listen to the sea

The first is the path of the walk, and the second is what the speaker listens to.

Yes. Bela can mean beautiful, lovely, or sometimes nice, depending on context.

With weather, English often says nice weather, so that is probably the most natural translation here. But literally bela vetero can also suggest beautiful weather.

So the exact English choice depends on style, not grammar.

Aŭ is a diphthong, pronounced roughly like ow in cow.

So:

• laŭ sounds roughly like low-oo said quickly, or more accurately like a single ow-type sound
• aŭskultos begins with that same aŭ sound

English speakers often find this sound easy once they notice it is one combined vowel sound.

It often means to walk, to take a walk, or to stroll.

So ni promenos laŭ la strando could be understood as:

• we will walk along the beach
• we will take a walk along the beach
• we will stroll along the beach

The exact tone depends on translation style, but it usually suggests a pleasant, non-hurried walk.