Mi amiga compró una revista en el aeropuerto porque una periodista hablaba de nuestro destino favorito.

Mi is the short possessive adjective used before a noun: mi amiga = my friend.

Mía is the long possessive pronoun/adjective, and it is not used in front of a noun in this way. You would use it in sentences like:

• La amiga es mía = The friend is mine
• Una amiga mía = a friend of mine

So in this sentence, mi amiga is the correct form.

Compró is the third person singular preterite of comprar.

It means he/she bought.

Here it refers to mi amiga, so:

• Mi amiga compró = My friend bought

The accent mark is important:

• compro = I buy / I am buying
• compró = he/she bought

This is a very common Spanish tense contrast.

• compró is in the preterite because it describes a completed action: she bought the magazine.
• hablaba is in the imperfect because it gives background information or describes something ongoing at the time: the journalist was talking.

So the idea is:

• one finished event: she bought
• one ongoing/background action: a journalist was talking

This is very natural in Spanish storytelling.

Yes. Periodista is a noun that can refer to either a man or a woman.

The ending -ista does not automatically mean feminine. The gender is usually shown by the article:

• el periodista = the male journalist
• la periodista = the female journalist
• un periodista
• una periodista

So una periodista tells you the journalist is female.

Because en means in / at, while a often shows movement to a place.

Here, the sentence is saying where she bought the magazine:

• en el aeropuerto = at the airport

If the meaning were to the airport, then you might see al aeropuerto.

Also, only a + el and de + el contract in Spanish:

• a + el = al
• de + el = del

But en + el does not contract, so it stays en el.

Because porque (one word, no accent) means because.

Spanish distinguishes several similar-looking forms:

• porque = because
• por qué = why
• el porqué = the reason
• por que = a less common combination in specific structures

In this sentence, it gives the reason, so porque is correct.

Because the verb hablar often takes de when you say what someone is talking about.

• hablar de algo = to talk about something
• hablar de alguien = to talk about someone

So:

• hablaba de nuestro destino favorito = was talking about our favourite destination

This is just the normal pattern of the verb.

Because both nuestro and favorito must agree with destino, which is a masculine singular noun.

• destino = masculine singular
• therefore: nuestro destino favorito

Agreement in Spanish depends on the noun, not on the speaker.

Compare:

• nuestro destino favorito = our favourite destination
• nuestra ciudad favorita = our favourite city

So if the noun changes gender, the adjectives and possessives change too.

In Spanish, descriptive adjectives often come after the noun.

So:

• destino favorito = favourite destination
• revista interesante = interesting magazine

Some adjectives can come before or after the noun, sometimes with a change in emphasis or meaning, but favorito very commonly comes after the noun.

So nuestro destino favorito is the most natural order here.

It could, but it would change the feeling.

• hablaba = was talking / used to talk
  This sounds like background or an ongoing action.
• habló = spoke / talked
  This sounds more like a completed event.

In this sentence, hablaba fits better because it sets the scene for why the friend bought the magazine.

The given word order is completely natural, but Spanish is fairly flexible.

For example, you could also say:

• Porque una periodista hablaba de nuestro destino favorito, mi amiga compró una revista en el aeropuerto.

This is still correct, though the original version sounds more neutral and natural in everyday use.

Spanish often changes word order for emphasis, but the standard order here is very good for learners to follow.