Learn Hardcore Spanish (Spain): En el refugio, una voluntaria calmó a los niños y les contó un cuento. - In the shelter, a female volunteer calmed the children and told them a story.

Without the a, los niños would sound more like a non‑personal object (which is wrong here, because children are people). With animals or things you don’t use the personal a (except in some special emotional cases):

Calmó a los perros. (dogs treated more like pets/family)
Calmó los ruidos. (no a, because ruidos are things)

Why do we say los niños and not just niños?

Spanish uses definite articles (like el, la, los, las) more often than English.

los niños = the children (a specific group that both speaker and listener know about)
plain niños without article would usually sound incomplete as a direct object here.

You might omit the article in some set expressions (for example, niños y niñas, on posters or slogans), but in a normal sentence like this, los niños is the natural choice: she calmed the children in that situation, not children in general.

What does En el refugio mean exactly, and why en instead of a?

En usually means in / at / on and is used for location.

En el refugio = in/at the shelter

You would use a to show movement or direction toward a place:

Fue al refugio. = She went to the shelter.
Estaba en el refugio. = She was in/at the shelter.

In your sentence we’re describing where the action happened (location), not where someone is going, so en el refugio is correct.

Why is there a comma after En el refugio?

En el refugio is an introductory phrase that sets the scene (time/place context) for the main action. Spanish often uses a comma after such initial phrases, especially when they’re longer than one word or can be separated naturally in speech.

En el refugio, una voluntaria calmó a los niños…

You could technically omit the comma in very short sentences, but writing it is clearer and more standard.

Why don’t we say ella? How do we know it’s “she” and not “he”?

Spanish usually drops subject pronouns (yo, tú, él, ella, etc.) unless they’re needed for emphasis or contrast. The verb ending already tells you the subject:

calmó is 3rd person singular (he / she / it calmed)
contó is also 3rd person singular (he / she / it told)

We know it’s she because the noun una voluntaria is feminine:

un voluntario = a male volunteer
una voluntaria = a female volunteer

So una voluntaria calmó… already gives you the subject and its gender. Adding ella would only be for emphasis, for example:

En el refugio, ella, una voluntaria, calmó a los niños… (very emphatic or contrastive)

Why is it una voluntaria here and not un voluntario?

Nouns for people’s roles or jobs often have masculine and feminine forms:

un voluntario (male volunteer)
una voluntaria (female volunteer)

The article and the noun must agree in gender and number:

un voluntario / unos voluntarios
una voluntaria / unas voluntarias

This sentence is talking about a female volunteer, so una voluntaria is used.

Why is it calmó and contó (with an accent) and not calmo / conto?

Calmó and contó are in the preterite (simple past) for él / ella / usted:

calmar → calmó (she calmed)
contar → contó (she told)

The accent mark shows the stress and also distinguishes forms:

calmo (no accent) could be yo calmo = I calm (present), or sometimes an adjective (calmo = calm)
calmó (with accent) = he/she/it calmed (completed action in the past)

Same with contar:

cuento = I tell
contó = he/she told

The accent is needed both for pronunciation and to mark the correct tense/form.

Why is the past tense here the preterite (calmó, contó) and not the imperfect (calmaba, contaba)?

Spanish has two main simple past tenses:

Preterite (pretérito indefinido) – completed actions, seen as whole events.
Imperfect (pretérito imperfecto) – ongoing, repeated, or background actions.

In your sentence, these are seen as finished actions:

She calmed them (finished)
She told them a story (finished)

So we use the preterite:

calmó = she calmed (once, complete event)
contó = she told (a specific story, complete event)

If you used the imperfect, calmaba / contaba, it would suggest ongoing background activity, like:

En el refugio, una voluntaria calmaba a los niños mientras llegaban más personas.
(She was calming the children while more people were arriving.)

Different aspect, not just a simple one‑time action.

What is the difference between contar and decir? Why les contó un cuento and not les dijo un cuento?

Both contar and decir involve communicating, but their usage differs:

contar = to tell in the sense of relate, narrate (stories, jokes, news, experiences)
decir = to say / to tell something to someone (statements, information, words)

Typical patterns:

contar un cuento / una historia / un chiste (to tell a story / a joke)
decir la verdad / decir algo / decir una palabra (to tell the truth / say something / say a word)

So:

les contó un cuento = she told them a story (narrated a story)
les dijo un cuento sounds wrong; decir doesn’t naturally take un cuento as its object.

Why is it les contó un cuento and not contó un cuento a los niños? Are both possible?

Both structures are possible and grammatical; they’re just different ways to express the indirect object.

Using an indirect object pronoun:
- Les contó un cuento. = She told them a story.
Using a prepositional phrase:
- Contó un cuento a los niños. = She told a story to the children.

You can also combine them in Spanish (this is very common and normal):

Les contó un cuento a los niños.

In that case, les is obligatory and a los niños simply clarifies who “les” refers to. Spanish allows (and often prefers) this kind of “doubling” with indirect objects.

In your original sentence, the reference is already clear from context, so les contó un cuento is enough.

Why is the pronoun les placed before contó and not after it?

Object pronouns like me, te, le, nos, os, les normally go before a conjugated verb:

Les contó un cuento. (standard word order)

They can attach after the verb only when the verb is an infinitive, gerund, or affirmative command:

Va a contarles un cuento. / Les va a contar un cuento.
Está contándoles un cuento. / Les está contando un cuento.
Contadles un cuento. (you all, tell them a story!)

With a simple, fully conjugated verb like contó, the modern standard is:

Les contó… (not contóles, which sounds archaic or poetic).

What exactly is the nuance of cuento? Could we use historia instead?

Both cuento and historia can be translated as story, but there’s a nuance:

cuento: usually a short, fictional story (like a fairy tale or bedtime story).
historia: more general — a story, narrative, or even history in some contexts.

In a context with children at a shelter, contar un cuento strongly suggests something like a children’s story, a tale to entertain or comfort them. You could say:

Les contó una historia.

That’s grammatically fine, but cuento sounds more like a typical children’s story or bedtime story, which fits this sentence especially well.