La guia del museu explica que aquesta artista també va treballar a la ciutat.

It can mean either, depending on context.

• la guia can be a female guide
• la guia can also be a guidebook

So la guia del museu could mean the museum guide or the museum guidebook. The verb explica works with both, so only the wider context tells you which one is intended.

Because de + el contracts in Catalan:

• de + el = del

So:

• la guia del museu = the guide of the museum / more naturally, the museum guide

This is very common in Catalan, just like:

• a + el = al

Because aquesta is the feminine singular form of this.

The noun artista is a common-gender noun, which means the noun form often stays the same for both male and female people. The gender is shown by the article, demonstrative, or adjective around it.

So:

• aquest artista = this male artist
• aquesta artista = this female artist

Even though artista ends in -a, it is not automatically feminine.

Va treballar is a past tense, specifically the periphrastic past in Catalan.

Structure:

• va
  • infinitive
• va treballar = worked

This is one of the most common ways to talk about completed past actions in Catalan, especially in everyday language.

No. In this sentence, va treballar does not mean went to work.

Although va comes from the verb anar (to go), in this grammar pattern it functions as part of a past tense:

• va treballar = worked

So here it is a single verbal expression, not the idea of physically going somewhere.

Because the sentence combines:

• a present action: La guia del museu explica... = The museum guide explains...
• a past action inside the explanation: ...que aquesta artista també va treballar... = ...that this artist also worked...

So the guide is explaining now, but what the guide says is about something that happened in the past.

Que introduces a subordinate clause, like that in English.

So:

• explica que... = explains that...

In English, that is often omitted:

• She explains that the artist worked there
• She explains the artist worked there

In Catalan, que is normally kept in this kind of sentence.

Here també means also, and its position shows that the idea being added is the action:

• aquesta artista també va treballar a la ciutat
• this artist also worked in the city

Putting també before the verb is very natural in Catalan.

You can move it in some sentences, but the emphasis changes:

• També aquesta artista va treballar a la ciutat = This artist too worked in the city
• Aquesta artista va treballar també a la ciutat = possible, but less neutral in this context

The accent shows both pronunciation and meaning.

• també = also
• the accent marks the stressed final syllable

Accent marks in Catalan are important and should be learned as part of the word.

Because a is very commonly used in Catalan for location, especially with cities and places in general.

So:

• treballar a la ciutat = to work in the city

You may also see en in some contexts or varieties, but a la ciutat is completely natural and standard here.

A little, yes, but the original order is the most neutral.

Standard order here is:

• La guia del museu = subject
• explica = main verb
• que... = subordinate clause

Inside the subordinate clause:

• aquesta artista = subject
• també va treballar = verb phrase
• a la ciutat = place

Catalan word order is fairly flexible, but changing it usually changes the emphasis. The given sentence is the most straightforward way to say it.