Jutro mam szczepienie, więc pytam, czy zastrzyk będzie bolał.

This is a very natural Polish way to say it.

Mam szczepienie literally means I have a vaccination, but in real usage it often means:

• I have a vaccination scheduled
• I’m getting vaccinated
• I have my vaccination tomorrow

Polish often uses mieć for appointments, scheduled events, and things you are due to undergo, for example:

• Mam wizytę u lekarza = I have a doctor’s appointment
• Mam egzamin = I have an exam

So Jutro mam szczepienie is idiomatic and natural.

They are related, but not the same.

• szczepienie = vaccination, immunization, or the vaccination procedure as a whole
• zastrzyk = injection, shot, the actual needle injection

So the sentence first talks about the whole event:

• Jutro mam szczepienie = Tomorrow I have a vaccination

Then it asks about the specific part that might hurt:

• czy zastrzyk będzie bolał = whether the injection will hurt

That is why both words appear.

Because the asking is happening now, not tomorrow.

The idea is:

• Tomorrow I have a vaccination
• so now I am asking whether the injection will hurt

So pytam means I’m asking or I ask in the present.

If you wanted to say that the asking will happen in the future, you would use something else, for example:

• zapytam = I will ask

So pytam is correct here because the speaker is asking already.

Because Polish usually leaves out subject pronouns when they are clear from the verb ending.

• mam already tells you it is I have
• pytam already tells you it is I ask / I’m asking

So adding ja is usually unnecessary unless you want emphasis, contrast, or clarification.

For example:

• Ja pytam, a on nie = I’m asking, but he isn’t

In the original sentence, no emphasis is needed, so leaving out ja is normal.

Here czy means whether or if and introduces an indirect yes-or-no question.

So:

• pytam, czy zastrzyk będzie bolał = I’m asking whether the injection will hurt

This is different from asking a direct question:

• Czy zastrzyk będzie bolał? = Will the injection hurt?

So czy can introduce both:

• a direct yes/no question
• an indirect yes/no clause after a verb like ask, know, wonder, etc.

This is a future form.

• będzie = will be
• bolał comes from boleć = to hurt

Together, będzie bolał means will hurt.

Polish often forms the future of imperfective verbs with będę / będziesz / będzie / będziemy / będziecie / będą plus either:

• the infinitive, or
• a past-like form that agrees with gender and number

So you can get patterns like:

• będzie boleć
• będzie bolał

Both can be correct, depending on style and structure.

Because it agrees with zastrzyk, which is a masculine singular noun.

• zastrzyk is masculine singular
• therefore the agreeing form is bolał

If the subject were neuter, you would get a neuter form:

• szczepienie będzie bolało = the vaccination will hurt

If the subject were feminine:

• rana będzie bolała = the wound will hurt

So the ending changes to match the grammatical gender and number of the subject.

Yes, both are possible, but the nuance is slightly different.

czy zastrzyk będzie boleć

• also means whether the injection will hurt
• uses the infinitive after będzie
• very normal Polish

czy zastrzyk zaboli

• uses the perfective verb zaboleć
• often suggests will it hurt at the moment, will it sting, will it start hurting

A rough distinction is:

• będzie bolał / będzie boleć = will be painful, will hurt
• zaboli = will hurt at that moment, will give pain

In everyday speech, people may use either depending on what exactly they mean.

It is in the accusative, because mieć normally takes a direct object in the accusative.

However, szczepienie is a neuter noun, and in the singular its nominative and accusative forms look the same.

So:

• nominative: szczepienie
• accusative: szczepienie

That is why there is no visible ending change.

Compare with a feminine noun, where the change is visible:

• książka = book
• mam książkę = I have a book

Here zastrzyk is the subject of the clause zastrzyk będzie bolał, so it is in the nominative.

The structure is:

• czy zastrzyk będzie bolał
• whether the injection will hurt

Since zastrzyk is doing the grammatical action of hurting, it stays in the nominative.

Yes, Polish word order is flexible.

Putting jutro first gives time information right away:

• Jutro mam szczepienie... = Tomorrow I have a vaccination...

This is very natural, because the speaker sets the scene first.

You could also say:

• Mam jutro szczepienie, więc pytam, czy zastrzyk będzie bolał

That is also correct. The difference is mainly emphasis and rhythm, not basic meaning.

Because Polish punctuation usually separates these parts of the sentence.

• comma before więc because it joins two clauses, like so
• comma before czy because czy zastrzyk będzie bolał is a subordinate clause

So the sentence naturally divides into:

• Jutro mam szczepienie
• więc pytam
• czy zastrzyk będzie bolał

Polish often uses commas a bit more systematically than English in subordinate structures.

A rough guide:

• jutro ≈ YOO-tro
• szczepienie ≈ shche-pye-NYE-nye
• więc ≈ vyents
• pytam ≈ PIH-tam
• czy ≈ a bit like chy, but with a harder Polish sound
• zastrzyk ≈ ZA-strzhik
• będzie ≈ BEN-jye
• bolał ≈ BO-wahw or BO-lahw, depending on how finely you represent Polish ł

A few useful pronunciation notes:

• szcz is a difficult cluster, roughly like a hard shch
• cz is like ch in chop, but retroflex and harder
• ń / nie in words like szczepienie gives a ny sound
• ł is pronounced like English w
• stress in Polish is usually on the second-to-last syllable

So:

• JU-tro
• szcze-PIE-nie
• PY-tam
• ZA-strzyk
• BO-lał