Learn Hardcore Spanish (Latin America): Mi prima quiere ser bombera para ayudar a las personas en un incendio. - My cousin wants to be a firefighter to help people in a fire.

In everyday Latin American Spanish you will still hear some people use the masculine bombero for women too, but using bombera is normal and widely accepted.

Why is there no una before bombera? Why not quiere ser una bombera?

With professions, Spanish normally leaves out the indefinite article (un/una) after ser when you’re just saying what someone is by profession:

Mi prima es bombera. = My cousin is a firefighter.
Quiere ser médico. = He/she wants to be a doctor.

You usually add un/una only when the profession is modified or emphasized:

Quiere ser una buena bombera. = She wants to be a good firefighter.
Es un bombero muy valiente. = He is a very brave firefighter.

So quiere ser bombera is the standard, neutral way to say “wants to be a firefighter.”

Why is it quiere ser and not quiere es?

Verbs like querer (to want) are followed by an infinitive when you say what someone wants to do:

Quiero comer. = I want to eat.
Queremos viajar. = We want to travel.
Mi prima quiere ser bombera. = My cousin wants to be a firefighter.

You never conjugate the second verb in this structure.
So quiere es is always wrong; it must be quiere ser.

Why is para used in para ayudar and not por ayudar?

Para + infinitive is used to express purpose or goal — “in order to”:

Estudio para aprender. = I study (in order) to learn.
Trabaja para pagar la universidad. = He works (in order) to pay for university.
Quiere ser bombera para ayudar… = She wants to be a firefighter in order to help…

Por + infinitive is used for reasons or causes, not goals:

Lo castigaron por llegar tarde. = They punished him for arriving late.

Here, we’re talking about her goal (the purpose of being a firefighter), so para ayudar is correct.

Why is it a las personas and not just las personas after ayudar?

Spanish uses the “personal a” before direct objects that are people (or person-like):

Veo a mi prima. = I see my cousin.
Respeto a mis padres. = I respect my parents.

The verb ayudar normally takes this a when the object is a person:

Ayudo a mi amigo. = I help my friend.
Ayudar a las personas. = To help people.

So a las personas is required; ayudar las personas sounds wrong to native speakers.

What is the difference between personas and gente? Could I say para ayudar a la gente?

Both personas and gente can mean people, but:

personas is a regular plural noun (feminine plural).
gente is grammatically singular (feminine singular) but means a group of people.

In this sentence, you can say:

Mi prima quiere ser bombera para ayudar a la gente en un incendio.

That’s completely natural too.

Difference in use:

personas sounds a bit more individual/neutral: specific people.
gente is more collective: “people” as a group or crowd.

Grammatically:

las personas son amables (plural verb)
la gente es amable (singular verb)

Why is it en un incendio and not en el incendio or en incendios?

En un incendio with un is like saying “in a fire / in a fire situation” in general — any typical fire, not one specific known fire.

en un incendio = in a (any) fire, during a fire.

If you say en el incendio, you’re pointing to a specific fire that speakers know about:

Mi prima ayudó a las personas en el incendio de ayer.
= My cousin helped people in yesterday’s fire.

En incendios (no article, plural) would mean “in fires (in general)” and is also possible:

Mi prima quiere ayudar a las personas en incendios.
This sounds a bit more abstract/generic.

The original en un incendio is a natural way to talk about the typical situation (a fire) without specifying one particular event.

Can I say durante un incendio instead of en un incendio?

Yes:

…para ayudar a las personas durante un incendio.

is also correct and clear.

en un incendio often feels like “in a fire situation / in a fire.”
durante un incendio emphasizes the time: “during a fire.”

Both are okay here, with only a small nuance of emphasis.

Why do we use present tense quiere even though this is about her future career?

Spanish often uses the present tense to talk about current desires, plans, or long-term intentions:

Quiero ser médico. = I want to be a doctor (in the future).
Ella quiere vivir en México. = She wants to live in Mexico.

The verb quiere describes what she wants now (her current desire), even though the thing she wants is in the future. This is normal and the most natural tense here.

Can I change the word order of a las personas and en un incendio?

Yes, Spanish word order is fairly flexible with prepositional phrases. All of these are grammatically correct:

…para ayudar a las personas en un incendio. (original)
…para ayudar en un incendio a las personas.
…para ayudar a las personas que estén en un incendio. (adds a nuance: “who are in a fire”)

The original version is the most neutral and natural, but moving en un incendio around is possible and still understandable.

Could I say para que ayude a las personas instead of para ayudar a las personas?

That would change the structure and meaning slightly.

para ayudar a las personas = in order to help people (same subject: mi prima both wants and will help).
para que ayude a las personas = in order that she may help people (subjunctive, often used when the subject of the second verb is different, or you need a full clause).

If you keep the same subject (mi prima), para + infinitive is the normal choice:

Mi prima quiere ser bombera para ayudar a las personas. ✅

You’d use para que + subjunctive more like:

Quiero que mi prima sea bombera para que ayude a las personas.
= I want my cousin to be a firefighter so that she (can) help people.