Post la pluvo la sablo estis pli malvarma, sed la ondoj ankoraŭ estis belaj.

Because post is a preposition, and nouns after prepositions normally do not take -n.

So:

• post la pluvo = after the rain

The -n ending is mainly used for:

• direct objects
• direction toward something in some expressions

Here, la pluvo is simply the object of the preposition post, so no -n is needed.

That phrase gives the time setting first: after the rain.

Esperanto often puts time expressions near the beginning of the sentence, just like English can:

• After the rain, the sand was cooler...

It could also be placed later, for example:

• La sablo estis pli malvarma post la pluvo...

Both are possible, but starting with Post la pluvo gives the time frame right away.

La is the definite article, meaning the.

So:

• la sablo = the sand
• sablo = sand / sand in general

Here, the sentence is talking about a specific sand in a specific situation, not sand in general, so la is natural.

Also, sablo is a mass noun, like English sand, so it is usually singular when talking about the substance in general.

Because sand is normally treated as a mass noun, not as separate countable items.

So:

• sablo = sand
• sabloj would mean kinds of sand or separate sands in a special context

In this sentence, it simply means the sand on the beach or in that place, so singular sablo is the normal choice.

Yes. Pli malvarma means more cold, which in natural English is usually cooler or colder, depending on context.

Esperanto often forms comparisons with:

• pli = more
• malvarma = cold / cool

So:

• pli malvarma = colder / cooler

This is very regular. Esperanto usually does not create separate comparative adjective forms like English cold → colder. Instead, it uses pli.

Because the comparison is understood from the context.

The sentence means the sand was cooler than before or cooler than it had been, but that second part is not stated explicitly.

If you wanted to state it explicitly, Esperanto would use ol for than:

• La sablo estis pli malvarma ol antaŭe.
• The sand was cooler than before.

So in the original sentence, ol is omitted because the comparison is implied.

Because malvarma is an adjective describing la sablo.

With esti (to be), Esperanto uses an adjective for the description:

• la sablo estis malvarma = the sand was cold/cool

If you used malvarme, that would be an adverb, and adverbs describe verbs, adjectives, or other adverbs, not nouns.

So:

• malvarma = cold, as a quality of the sand
• malvarme = coldly / in a cold way

Here we need the adjective.

Because ondoj is plural, and adjectives in Esperanto agree with the nouns they describe.

So:

• ondo = wave
• ondoj = waves

And:

• bela = beautiful
• belaj = beautiful (plural)

Since the subject is plural, the adjective must also be plural:

• la ondoj estis belaj = the waves were beautiful

This adjective agreement is a very important Esperanto rule.

Ankoraŭ means still.

So:

• la ondoj ankoraŭ estis belaj = the waves were still beautiful

It shows that even after the rain, that quality had not changed.

In other contexts, ankoraŭ can also sometimes be translated as yet, depending on the sentence.

Because it naturally modifies the whole idea that the waves were still beautiful.

Esperanto word order is somewhat flexible, but ankoraŭ is often placed before the word or phrase it affects. Here it affects the statement estis belaj.

So this placement is natural:

• la ondoj ankoraŭ estis belaj

You may also see slightly different placements in Esperanto, but this one is straightforward and common.

Because the sentence has two clauses with different subjects:

• la sablo estis pli malvarma
• sed la ondoj ankoraŭ estis belaj

Repeating estis makes the structure clear and natural. English does the same here:

• the sand was cooler, but the waves were still beautiful

Since the subjects are different, repeating the verb is expected.

Sed means but.

It introduces a contrast:

• the sand was cooler
• but the waves were still beautiful

So the sentence is contrasting two facts after the rain: one thing changed in a less pleasant way, while another pleasant thing remained true.

Yes. Esperanto word order is fairly flexible, as long as the grammar stays clear.

For example, these are possible:

• La sablo estis pli malvarma post la pluvo, sed la ondoj ankoraŭ estis belaj.
• Post la pluvo, la sablo estis pli malvarma, sed la ondoj estis ankoraŭ belaj.

The original version is good and natural. Starting with Post la pluvo emphasizes the time setting first.

Because sed joins two full clauses, and Esperanto commonly uses a comma before conjunctions like sed in that situation.

Here the two clauses are:

• la sablo estis pli malvarma
• la ondoj ankoraŭ estis belaj

So the comma helps separate the two contrasting parts clearly.