Si empieza la tormenta, las niñas pueden resguardarse en la entrada del museo.

In Spanish, after si meaning if, a real or likely future condition normally uses the present indicative, not the future tense.

So Spanish says:

• Si empieza la tormenta... = If the storm starts...

Even though the event may happen later, Spanish still uses empieza.

This is very common:

• Si llueve, nos quedamos en casa.
• Si vienes mañana, te ayudo.

English often uses the present here too, but learners sometimes expect a future form in Spanish because the meaning is future. In this structure, empieza is exactly what you want.

Because after si for a normal, possible condition, Spanish uses the indicative, not the subjunctive.

So:

• Si empieza la tormenta... = correct
• Si empiece la tormenta... = not correct in standard Spanish for this meaning

The subjunctive is not normally used after si in this kind of sentence. A very useful pattern is:

• Si + present indicative, then another verb in present, future, or imperative

Examples:

• Si tengo tiempo, voy.
• Si viene, hablaremos con ella.
• Si ves a Ana, dile la verdad.

Spanish often uses the definite article more than English does.

Here, la tormenta means something like the storm, but not necessarily a specific storm already fully identified in the conversation. It can simply refer to the storm that may start, understood from the situation.

Weather and natural phenomena often appear with the article in Spanish:

• la lluvia
• el viento
• la nieve
• la tormenta

So si empieza la tormenta sounds natural, while leaving out the article would sound wrong here.

Because las niñas refers to a specific group: the girls.

Without the article, niñas would sound more general or incomplete in this sentence. Spanish often uses articles with nouns when talking about known or identifiable people or things.

So:

• las niñas = the girls
• niñas = girls, in a more general sense

In this sentence, we are talking about particular girls, not girls in general.

Pueden can express several ideas, including:

• ability = they can
• permission = they may
• possibility/practical option = they can

In this sentence, the most natural reading is practical possibility or available option:

• the girls can take shelter in the museum entrance

It is not mainly about physical ability, and it is not necessarily formal permission either. It means that this is something they are able to do in that situation.

Because resguardarse means to shelter oneself or to take cover.

The se shows that the action comes back to the subject:

• las niñas pueden resguardarse = the girls can shelter themselves / take shelter

Compare:

• resguardar algo = to protect or shelter something
• resguardarse = to protect oneself, to take shelter

So the reflexive/pronominal form is the natural one here because the girls are protecting themselves from the storm.

Yes, resguardarse is a good, natural choice, especially in contexts involving weather, wind, rain, or danger.

Some similar alternatives are:

• refugiarse = to take refuge
• cobijarse = to shelter oneself
• ponerse a cubierto = to get under cover

The nuance of resguardarse is often that someone moves to a protected place to avoid rain, wind, cold, or similar conditions.

So this sentence sounds very natural for a storm situation.

En la entrada del museo means in/at the entrance of the museum.

Here:

• en = in / at
• la entrada = the entrance
• del museo = of the museum

Spanish uses en because the girls would be located in that entrance area, using it as shelter.

A learner might wonder about a la entrada del museo. That expression usually means at the entrance of the museum in a more locational sense, often focusing on the point or place. En la entrada suggests being in that entrance space itself, which fits the idea of taking shelter.

Because de + el contracts to del in Spanish.

So:

• de + el museo → del museo

This contraction is required in almost every case.

The only common exception is when el is part of a proper name:

• de El Escorial = not del Escorial, if the official name is El Escorial

But here el museo is just a normal noun phrase, so del museo is correct.

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

• Si empieza la tormenta, = conditional part
• las niñas pueden resguardarse en la entrada del museo. = main statement

This is very common when the conditional clause comes first.

If the order changes, the comma is often not used:

• Las niñas pueden resguardarse en la entrada del museo si empieza la tormenta.

Both word orders are natural, but putting the si clause first slightly emphasizes the condition.

The ñ is pronounced like the ny sound in canyon, though not exactly identical in every accent.

So niñas sounds roughly like:

• NEE-nyas

Breakdown:

• ni = nee
• ñas = nyas

This letter is important because n and ñ change meaning:

• ano and año are completely different words
• nina and niña would not be pronounced the same

So make sure to pronounce the ñ clearly.