Muszę zdecydować, czy chcę pracować na etat w tej firmie.

Muszę is the 1st person singular form of musieć (to have to / must).

So:

• muszę = I have to / I must
• musisz = you have to
• musi = he/she/it has to

In this sentence, Muszę zdecydować... means I have to decide...

After muszę, Polish normally uses an infinitive, just like English often does:

• Muszę zdecydować = I have to decide

So zdecydować is the infinitive.

There is also an aspect difference:

• decydować = imperfective, focusing on the process or repeated deciding
• zdecydować = perfective, focusing on reaching a decision

Here, the speaker means I need to make the decision / come to a decision, so zdecydować is the natural choice.

Here czy means whether / if in an indirect question.

So:

• Muszę zdecydować, czy chcę... = I have to decide whether I want...

This czy is used when introducing a choice or uncertainty inside a larger sentence.

It is not the same as czy used at the beginning of a yes/no question, although it is related.

Examples:

• Nie wiem, czy przyjdzie. = I don't know if/whether he will come.
• Muszę sprawdzić, czy to działa. = I have to check whether this works.

Chcę is the 1st person singular of chcieć (to want), and it is followed by an infinitive:

• chcę pracować = I want to work

This is very similar to English:

• I want to work
• Chcę pracować

So the structure is:

• chcieć + infinitive
• musieć + infinitive

In the full sentence, you get a chain:

• Muszę zdecydować = I have to decide
• czy chcę pracować = whether I want to work

Na etat means as a salaried employee / in a regular employed position, often understood as full-time employment, though context matters.

The noun etat refers to a regular job position, especially one where you are employed by a company rather than freelancing or working on a temporary contract.

So:

• pracować na etat = to work as a regular employee
• often contrasted with:
  • na zlecenie
  • na umowę o dzieło
  • na własnej działalności

A learner-friendly translation is often:

• to work full-time or
• to work as an employee

But the exact nuance is more about the type of employment arrangement than simply the number of hours.

Because Polish uses the fixed expression pracować na etat.

Many Polish combinations with prepositions simply have to be learned as set phrases. English speakers often want a one-to-one rule, but usually the best approach is to memorize the whole chunk:

• pracować na etat
• pracować na pół etatu = to work part-time
• być na urlopie = to be on leave
• iść na studia = to go to university

So in this case, na is just the preposition required by the expression.

W tej firmie is in the locative case because it follows w meaning in (location).

Breakdown:

• firma = company
• tej = this in the feminine singular locative/genitive/dative form
• firmie = locative singular of firma

So:

• w tej firmie = in this company

This is a very common pattern:

• w domu = in the house
• w szkole = in the school
• w tej firmie = in this company

Because ta firma changes form after w.

The basic nominative form is:

• ta firma = this company

But after w for location, Polish uses the locative:

• w tej firmie

So both words change:

• ta → tej
• firma → firmie

This kind of agreement is very important in Polish: the demonstrative adjective must match the noun in gender, number, and case.

Not completely. Polish word order is more flexible than English, but the original sentence is very natural and neutral:

• Muszę zdecydować, czy chcę pracować na etat w tej firmie.

You might also hear variations for emphasis, such as:

• Muszę zdecydować, czy w tej firmie chcę pracować na etat.

That version puts more focus on w tej firmie.

Still, for learners, the original order is the safest and most natural choice.

There is one comma here, not two:

• Muszę zdecydować, czy chcę pracować na etat w tej firmie.

The comma appears before czy because it introduces a subordinate clause:

• main clause: Muszę zdecydować
• subordinate clause: czy chcę pracować na etat w tej firmie

In Polish, commas before subordinate clauses are used more regularly than in English, so punctuation is something learners should pay attention to.

Yes, and it is very natural.

• Muszę zdecydować... = I have to decide...
• Muszę się zdecydować... = I have to make up my mind / decide

The version with się often sounds a bit more like settling on a choice.

For example:

• Muszę się zdecydować, czy chcę pracować na etat w tej firmie.

This is probably even more common in everyday speech.

Both are understandable, but zdecydować się is often the idiomatic verb for to decide in the sense of making up one’s mind.

No, not in this sentence.

Use czy for whether / if in an indirect question:

• Muszę zdecydować, czy chcę... = I have to decide whether I want...

But:

• jeśli = if in a conditional sense
• gdyby = if in a hypothetical sense

So these mean different things:

• Nie wiem, czy przyjdzie. = I don’t know whether he’s coming.
• Jeśli przyjdzie, porozmawiamy. = If he comes, we’ll talk.
• Gdyby przyszedł, porozmawialibyśmy. = If he came, we would talk.

In your sentence, the meaning is whether, so czy is the correct word.

A native speaker would understand it as something like:

• I have to decide whether I want to work as a regular employee in this company.

The tone is natural and standard. It suggests the speaker is considering a specific employment arrangement and hasn’t made up their mind yet.

The sentence sounds like something you might say when comparing options, for example:

• working na etat
• freelancing
• working elsewhere
• not taking the job at all