Subite ekpluvis, kaj granda ŝtormo venis de la maro.

The prefix ek- usually shows the beginning of an action, often with a sudden feel.

So:

• pluvis = it rained / it was raining
• ekpluvis = it began to rain / it suddenly started raining

That fits very well with subite, because both suggest a sudden change.

You will see ek- with many verbs, for example:

• ekkuris = started running
• ekparolis = started speaking
• ekridis = burst out laughing / started laughing

In Esperanto, weather verbs are often used without a subject. English needs a dummy subject, as in it is raining, but Esperanto does not.

So:

• Pluvas = it is raining
• Neĝas = it is snowing
• Ekpluvis = it began to rain

There is no need to add a separate word for it.

Because subite is an adverb, and adverbs in Esperanto end in -e.

Here it modifies the whole event, meaning suddenly.

Compare:

• subita ŝtormo = a sudden storm
• subite ekpluvis = it suddenly began to rain

So:

• -a = adjective, used with nouns
• -e = adverb, used with verbs, adjectives, or whole clauses

Because granda describes the noun ŝtormo, so it must be an adjective, and adjectives end in -a.

• granda ŝtormo = a big storm

Grande is an adverb, so it would describe how something happens, not what kind of storm it is.

Also, granda matches ŝtormo:

• singular
• not accusative
• so no extra -j or -n

If it were plural, you would get grandaj ŝtormoj.

The ending -is marks the past tense in Esperanto.

So:

• veni = to come
• venis = came

And:

• pluvi = to rain
• ekpluvis = began to rain

One nice feature of Esperanto is that tense endings do not change with person:

• mi venis = I came
• li venis = he came
• ili venis = they came

The verb form stays the same.

Here de means from, showing origin or source.

So de la maro means from the sea.

The parts are:

• de = from / of
• la = the
• maro = sea

In this sentence, it tells you where the storm came from.

La is the definite article, meaning the.

Esperanto has only one article:

• la = the

It does not change for gender, number, or case, although it can appear with an -n in poetry or rare styles, which beginners usually do not need to worry about.

Here la maro means the sea, probably referring to the specific sea near the scene being described.

Yes. Esperanto word order is fairly flexible.

The original order is neutral and straightforward:

Subite ekpluvis, kaj granda ŝtormo venis de la maro.

But you could also say:

De la maro venis granda ŝtormo.

That version puts more focus on de la maro.

Because Esperanto uses endings to show grammar, word order can move around more than in English, especially when there is no danger of confusion. Still, the most common order is usually similar to English.

Kaj is the normal Esperanto word for and.

It joins the two parts of the sentence:

• Subite ekpluvis
• granda ŝtormo venis de la maro

So it simply connects two related events.

The letter ŝ is pronounced like English sh in ship.

So ŝtormo begins with a sht- sound.

A rough pronunciation guide:

• ŝtormo ≈ SHTOR-mo
• subite ≈ su-BI-te
• ekpluvis ≈ ek-plu-VIS
• venis ≈ VE-nis
• maro ≈ MA-ro

Remember that Esperanto normally stresses the second-to-last syllable:

• suBIte
• ekpluVIS
• GRANda
• ŜTORmo
• VEnis
• MAro