Learn Hardcore Spanish (Spain): El guía del museo nos contó que en diciembre vienen muchos turistas extranjeros. - The guide at the museum told us that in December many foreign tourists come.

A person who guides
- El guía / la guía = the (tour) guide
A guidebook / manual (always feminine as an object)
- La guía turística = the tourist guidebook
- La guía telefónica = the phone book

In your sentence, el guía del museo clearly refers to a person who works as a guide at the museum, not a book.

Why is it del museo and not de el museo?

Spanish has a mandatory contraction:

de + el → del

So:

de el museo is grammatically incorrect.
It must be del museo = “of the museum / from the museum.”

This only happens with the masculine singular article el.
For example:

de la casa (not dela)
de los museos (not dellos)

What does nos do in nos contó, and why is it before the verb?

Nos is an indirect object pronoun meaning “to us.”

contar algo a alguien = to tell something to someone
El guía nos contó… = “The guide told us…”

Position:

In standard sentences, these pronouns go before a conjugated verb:
- nos contó, me dijo, les explicaron
You cannot say contó nos in this context; it sounds wrong in Spanish.
With infinitives or gerunds, they can attach to the end:
- va a contarnos = “he is going to tell us”
- está contándonos = “he is telling us”

What’s the difference between contar and decir here? Could I say nos dijo instead of nos contó?

Both contar and decir can work with que + clause, but they have different nuances:

contar = to tell, often with a sense of relating, narrating, explaining
- El guía nos contó que… suggests he told us / explained / related some information.
decir = to say / tell in a more neutral way
- El guía nos dijo que… = “The guide told us that…”

In this sentence, nos contó is very natural because guides are typically explaining or narrating things to visitors.
Nos dijo is also grammatically correct, just a bit less “story-like.”

Why is contó in the preterite and not contaba?

Contó (preterite) presents the action as completed, at a specific moment in the past:
- “At some particular time, the guide told us this.”
Contaba (imperfect) would focus on the ongoing / repeated / background nature of the telling:
- El guía del museo nos contaba que…
  → “The guide (used to) tell us / was telling us that…”

In your sentence, contó matches the idea of one specific time he told you this piece of information.

What is the role of que in nos contó que en diciembre…? Can it be omitted like in English?

Here que is a conjunction introducing a subordinate clause:

nos contó que… = “(he) told us that…”

In Spanish, this que is not optional in this structure.
You cannot drop it the way you sometimes can in English:

English: “He told us (that) in December many tourists come.”
Spanish: must be nos contó que en diciembre vienen…,
not nos contó en diciembre vienen…

Why is it en diciembre, without an article, and not en el diciembre?

In Spanish, months are usually used without an article when you mean them in a general or habitual sense:

en diciembre = “in December” (generally, every December)
en marzo, en julio, etc.

Using an article would sound marked or specific, like a particular December already known from context:

en el diciembre de 2020 = “in the December of 2020”

Here, en diciembre talks about what normally happens in that month, so no article is the natural choice.

Why is vienen in the present tense instead of a future form like vendrán?

Spanish often uses the simple present to talk about:

Habitual actions
Scheduled or regular events

So:

En diciembre vienen muchos turistas extranjeros.
= “In December, many foreign tourists come.”
(That’s what happens every December, as a regular pattern.)

If you said vendrán, it would sound more like a prediction about a specific future December:

En diciembre vendrán muchos turistas extranjeros.
= “Many foreign tourists will come in December (this coming one).”

Your sentence focuses on what normally happens, so the present vienen is correct.

Who is the subject of vienen? Why does it come after the verb?

The subject of vienen is:

muchos turistas extranjeros

Spanish often allows flexible word order. Putting the subject after the verb is very common, especially when:

You’re introducing new information, or
You want to highlight the time expression first.

So:

En diciembre vienen muchos turistas extranjeros.
(Time → verb → subject)

You could also say:

En diciembre muchos turistas extranjeros vienen.
Muchos turistas extranjeros vienen en diciembre.

All are grammatically correct; the original order is very natural and common.

Why muchos turistas extranjeros and not muchas turistas extranjeras?

Agreement in Spanish follows gender and number:

turista is a common-gender noun ending in -a:
- el turista (male tourist)
- la turista (female tourist)

If you’re talking about a mixed group or not specifying gender, Spanish normally uses the masculine plural:

muchos turistas extranjeros
= many tourists (male or mixed) from abroad

If you were explicitly referring only to women, you’d say:

muchas turistas extranjeras
= many female foreign tourists

So muchos and extranjeros are masculine plural to match (los) turistas in the mixed/unspecified sense.

Why is the adjective extranjeros placed after turistas?

The common, neutral position for most adjectives in Spanish is after the noun:

turistas extranjeros = foreign tourists
museo interesante = interesting museum
ciudad grande = big city

Some adjectives can go before or after, often with a change in nuance (e.g. un gran museo vs un museo grande), but extranjero normally goes after in this meaning (“foreign”/“from abroad”).

Putting it before, extranjeros turistas, would either sound unnatural or change the focus in a strange way, so turistas extranjeros is the standard form.

Why do guía and contó have accent marks?

The accent marks show where the stress falls and sometimes prevent a diphthong:

guía
- Without the accent, guia would tend to be pronounced as one syllable for “u + i” (a diphthong).
- With the accent, guía = gu-í-a (three syllables), stressing -í-.
- This matches the real pronunciation: [ˈɡi.a].
contó
- Without the accent, conto would be stressed on the second-to-last syllable (Spanish default): CON-to.
- The accent mark puts stress on the last syllable: con-TÓ.
- This is the correct stress pattern for the 3rd person singular preterite of contar.

So the accents tell you both where to stress and, in the case of guía, how to break the vowels into separate syllables.