Si la propietaria no arregla la caldera, pondré una queja.

This is the normal pattern for a real, possible future condition in Spanish:

• Si
  • present indicative
• main clause in the future (or sometimes another form like imperative)

So:

• Si la propietaria no arregla la caldera, pondré una queja.

Literally, the structure is:

• If the landlady/owner doesn’t fix the boiler, I will file a complaint.

This is the Spanish equivalent of the English first conditional.

Because after si for a real future condition, Spanish normally uses the present indicative, not the future.

So these are correct:

• Si la propietaria no arregla la caldera, pondré una queja.
• Si la propietaria no viene, me iré.

These are not standard:

• Si la propietaria no arreglará la caldera...
• Si la propietaria no vendrá...

This is a very common difference from English. Even though English refers to the future with if she doesn’t fix, Spanish also uses the present: si no arregla.

Propietaria means female owner or landlady, depending on context.

It comes from propietario / propietaria = owner.

In housing contexts, learners may also hear:

• la dueña = the female owner
• la casera = the landlady
• la arrendadora = the female landlord/lessor, more formal/legal

So la propietaria is correct and clear, but depending on the situation, another word might sound more natural.

Because the sentence refers to a woman.

Spanish nouns and adjectives often show gender:

• el propietario = the male owner
• la propietaria = the female owner

So the article and noun both match the person being talked about.

Arreglar often means to fix, to repair, or to sort out.

Here, with la caldera, it means fix/repair:

• arreglar la caldera = to fix the boiler

Other common meanings of arreglar depend on context:

• arreglar un coche = fix a car
• arreglar un problema = sort out a problem
• arreglarse = get ready / make oneself look neat

So in this sentence, arregla is simply fixes.

In Spain, la caldera usually means the boiler, especially the one used for hot water and/or heating in a home.

Depending on the country or situation, English speakers might think of:

• boiler
• water heater
• heating unit

But boiler is usually the safest translation for Spain.

Pondré is the first person singular future of poner:

• yo pondré = I will put / I will make / I will file

In this sentence, poner una queja means to make/file a complaint.

So:

• pondré una queja = I’ll file a complaint

Also, poner is irregular in the future:

• poner → pondr-
• yo pondré
• tú pondrás
• él/ella pondrá

It does not become poneré.

Because Spanish often uses verb-noun combinations that do not match English word for word.

Here, poner una queja is an idiomatic expression meaning:

• to make a complaint
• to file a complaint

Even though poner often literally means to put, that is not the best translation in this sentence.

This is very common in Spanish. For example:

• poner una denuncia = file a report / make a formal complaint
• poner una multa = issue a fine

So you should learn poner una queja as a chunk.

Yes, it is understandable and natural enough. But in Spain, people also very commonly say:

• poner una reclamación = to file a formal complaint
• presentar una queja = to submit a complaint
• poner una hoja de reclamaciones = to ask for / file an official consumer complaint form

So poner una queja is fine, but if the context is a more official complaint, poner una reclamación may sound even more specific.

Because the speaker is referring to a complaint, not a specific complaint already known to both speakers.

• una queja = a complaint
• la queja = the complaint

Using una is normal when introducing something for the first time:

• Si la propietaria no arregla la caldera, pondré una queja.

If there were already a specific complaint being discussed, la queja could be possible in another context.

Because the sentence starts with the if-clause:

• Si la propietaria no arregla la caldera, pondré una queja.

In writing, when the conditional clause comes first, Spanish normally uses a comma before the main clause.

If you reverse the order, the comma is usually not needed:

• Pondré una queja si la propietaria no arregla la caldera.

Both versions mean the same thing.

Yes. Both are possible.

• Pondré una queja = I will file a complaint
• Voy a poner una queja = I’m going to file a complaint

In many everyday conversations, ir a + infinitive is very common and can sound slightly more immediate or conversational.

So this would also be natural:

• Si la propietaria no arregla la caldera, voy a poner una queja.

Yes. The most common alternatives are:

• Si la propietaria no arregla la caldera, pondré una queja.
• Pondré una queja si la propietaria no arregla la caldera.

Both are correct.

The first one puts the condition first, which is very common when you want to emphasize the warning or condition.

It depends on tone and context, but it often sounds like a warning or a statement of intended action.

• neutral: If she doesn’t fix it, I’ll file a complaint.
• firmer / more threatening: said angrily or emphatically

So grammatically it is neutral, but pragmatically it can sound strong.

There are two key verbs:

• arregla

  • from arreglar
  • third person singular, present indicative
  • here: she fixes / she repairs

• pondré

  • from poner
  • first person singular, future
  • here: I will file / I will make

So the sentence combines a present tense in the si-clause with a future tense in the result clause.

Usually yes in this kind of sentence, because the subject is understood from context.

In the full sentence, la propietaria makes it clear:

• Si la propietaria no arregla la caldera...

If you had already mentioned her, you could drop the noun and just say:

• Si no arregla la caldera, pondré una queja.

Spanish often leaves out subject pronouns and sometimes repeated nouns when the meaning is clear.