En el folleto de la exposición explican de qué trata la colección permanente.

Explican is the third person plural of explicar in the present tense.

In Spanish, this form is often used when the speaker does not want to say exactly who the people are. So here it means something like:

• they explain
• people explain
• it explains in a looser English sense, referring to what the brochure says

The implied subject could be the museum staff, the people who made the brochure, or just an unspecified they.

If you said explica, that would mean he/she/it explains, and it would sound as if there were one clear subject.

It is unspecified.

Spanish often uses the third person plural this way when the action matters more than the person doing it. So explican does not necessarily mean a group of named people standing there and explaining; it can simply mean:

• they explain
• the brochure explains
• it says in the brochure

English does something similar with vague they.

En el folleto means in the brochure.

Here, en is used because the information is found inside / in the brochure. Spanish uses en for this kind of location, just as English uses in:

• En el libro... = in the book
• En la revista... = in the magazine
• En el folleto... = in the brochure

So the sentence is setting the place where the explanation appears.

This means the brochure of the exhibition, or more naturally in English, the exhibition brochure.

Breakdown:

• el folleto = the brochure
• de la exposición = of the exhibition

Spanish often uses de where English might prefer a noun used like an adjective:

• el museo de la ciudad = the city museum
• la sala de lectura = the reading room
• el folleto de la exposición = the exhibition brochure

This is a very common question for English speakers because exhibition looks like it should match exhibición, but in museum contexts Spanish usually uses exposición.

So:

• exposición = exhibition, exhibit, display
• exhibición usually means more like a performance, demonstration, or show of skill

For a museum or art show, exposición is the normal word.

De qué trata means what it is about.

The verb tratar can mean to be about or to deal with when used with de.

So:

• La novela trata de la guerra. = The novel is about war.
• ¿De qué trata? = What is it about?

In your sentence:

• de qué trata la colección permanente = what the permanent collection is about

Because the verb tratar in this meaning normally goes with de.

You ask:

• ¿De qué trata la colección permanente? = What is the permanent collection about?

When that question becomes part of a larger sentence, the de stays:

• explican de qué trata la colección permanente

So de qué is not optional here; it belongs to the verb pattern.

Yes, it is the same verb, tratar, but it can have different meanings depending on the structure.

Common patterns:

• tratar de + infinitive = to try to do something

  • Trato de aprender español. = I try to learn Spanish.

• tratar de + topic / subject = to be about

  • El libro trata de historia. = The book is about history.

• tratar a alguien = to treat someone

  • Tratan bien a los visitantes. = They treat visitors well.

So here, trata de means is about, not tries to.

Because it is an interrogative word.

Even though this is not a direct question with question marks, it is still an embedded question:

• ¿De qué trata la colección permanente?
• Explican de qué trata la colección permanente.

In both cases, qué keeps the accent because it means what in a question sense.

Without the accent, que usually has other functions, such as that.

Because Spanish keeps the structure of the indirect question quite close to the direct question.

Direct question:

• ¿De qué trata la colección permanente?

Embedded question:

• Explican de qué trata la colección permanente.

After de qué, the verb trata comes before the subject la colección permanente, which is very natural in Spanish question-style structures.

English learners often expect a more English-like order, but Spanish commonly keeps this pattern.

In a museum or gallery context, la colección permanente means the permanent collection: the works or objects that belong to the institution and are normally on long-term display.

This contrasts with a temporary exhibition, for example:

• la exposición temporal = the temporary exhibition
• la colección permanente = the permanent collection

So the sentence is saying that the brochure explains what the museum's regular collection is about.

Spanish uses definite articles more often than English.

Here they all point to specific things:

• el folleto = the brochure
• la exposición = the exhibition
• la colección permanente = the permanent collection

In English, you might sometimes drop an article or use a noun more flexibly, but in Spanish these articles sound natural and expected.

Yes. A very natural alternative would be:

• En el folleto de la exposición se explica de qué trata la colección permanente.

This uses se to make the sentence more impersonal, something like:

• it is explained in the exhibition brochure...
• the brochure explains...

Both versions are possible, but they feel slightly different:

• explican = vague they explain
• se explica = impersonal / passive-like style

The original sentence is still completely natural.

Both are in the present indicative:

• explican = they explain
• trata = it is about / it deals with

This present tense is used for current, factual information. In context, it means that the brochure currently gives that explanation.

Yes, in many contexts you could say:

• explican de qué va la colección permanente

Ir de can also mean to be about, and it is very common in everyday Spanish.

However:

• de qué trata sounds a bit more neutral and standard
• de qué va is a bit more conversational

For a museum brochure sentence, de qué trata fits very well.