Karetka przyjechała po dziesięciu minutach, a lekarz od razu sprawdził, czy pacjent jest przytomny.

Because karetka is a feminine noun in Polish, and the past tense agrees with the gender of the subject.

So:

• przyjechał = masculine singular
• przyjechała = feminine singular
• przyjechało = neuter singular

Since karetka means ambulance and is feminine, you say karetka przyjechała.

Polish does not have articles. There is no separate word for a, an, or the.

So:

• karetka can mean an ambulance or the ambulance
• lekarz can mean a doctor or the doctor
• pacjent can mean a patient or the patient

The exact meaning comes from the context.

Here po means after, and in this time expression it takes the locative case.

That is why:

• dziesięć becomes dziesięciu
• minuty becomes minutach

So:

• po dziesięciu minutach = after ten minutes

This is a very common Polish pattern for saying that something happened after a period of time.

These expressions mean different things.

• po dziesięciu minutach = after ten minutes
• za dziesięć minut = in ten minutes

In this sentence, the idea is that ten minutes passed, and then the ambulance arrived. That is why po is the correct choice.

In this sentence, a links two clauses and introduces a shift to a new subject: first karetka, then lekarz.

Very roughly:

• i = and
• ale = but
• a = and, while, whereas, depending on context

Here a is natural because it smoothly moves from one event to the next with a different subject:

• Karetka przyjechała..., a lekarz...

Using i would also be possible in some contexts, but a sounds very natural in narration like this.

Od razu means immediately, right away, or straight away.

It is a fixed expression. In this sentence:

• lekarz od razu sprawdził = the doctor checked immediately

It suggests there was no delay.

This is a question of aspect, which is very important in Polish.

• sprawdził is perfective
• sprawdzał is imperfective

Here sprawdził is used because the doctor performed one complete checking action.

So:

• sprawdził = he checked, he completed the check
• sprawdzał = he was checking, he used to check, or the action is viewed as ongoing or repeated

In this sentence, the completed action is what matters, so sprawdził is the natural choice.

Czy introduces an indirect yes or no question. In English, this is usually whether or sometimes if.

So:

• sprawdził, czy pacjent jest przytomny = he checked whether the patient was conscious

This is different from jeśli, which usually means if in a conditional sense, like if it rains.

So here:

• czy = whether
• jeśli = if, in the sense of condition

Polish often keeps the present tense in this kind of subordinate clause when the state is true at the time of checking.

So:

• sprawdził, czy pacjent jest przytomny = he checked whether the patient is conscious

Even though the main verb is in the past, the condition being checked is understood as current at that moment.

English often shifts this to was conscious, but Polish does not need to do that in the same way. Using był here would suggest a different time reference and is not the natural choice in this sentence.

Przytomny means conscious or awake and aware.

It is an adjective, and adjectives in Polish must agree with the noun they describe.

Here:

• pacjent is masculine singular
• so the adjective is przytomny

Compare:

• pacjent jest przytomny = the male patient is conscious
• pacjentka jest przytomna = the female patient is conscious
• dziecko jest przytomne = the child is conscious

Yes. Polish word order is fairly flexible, because endings carry a lot of the grammar.

This sentence has a very natural, neutral order:

• Karetka przyjechała po dziesięciu minutach, a lekarz od razu sprawdził, czy pacjent jest przytomny.

But other orders are possible for emphasis, for example:

• Po dziesięciu minutach karetka przyjechała...
• Lekarz od razu sprawdził, czy pacjent jest przytomny.

Changing the order can change what sounds most important, but the basic meaning stays the same.