Jeśli przełożona zmieni grafik, mój dyżur skończy się wcześniej.

Because przełożona is the feminine form of supervisor / superior / boss, while przełożony is the masculine form.

• przełożona = a female supervisor
• przełożony = a male supervisor

So the sentence tells you that the supervisor is a woman.

In this context, grafik means a work schedule, shift schedule, or roster.

It does not usually mean a graphic or image here. In workplace Polish, zmienić grafik commonly means:

• change the schedule
• change the shift plan
• rearrange the roster

So this is about work timing, not design.

Because zmienić is a perfective verb, and in Polish perfective verbs use a present-looking form to express the future.

So:

• zmieni = will change
• not changes in the ordinary present-time sense

This is very common in Polish. With perfective verbs, the so-called present form often refers to a completed future action.

Compare:

• zmienia = is changing / changes habitually (imperfective)
• zmieni = will change / changes once and completes it (perfective)

Here the meaning is: if the supervisor changes the schedule.

Polish often does not need a separate word like English will.

There are two main ways Polish expresses the future:

1. Perfective verb in a present-looking form

   • zmieni = will change
   • skończy się = will end

2. będzie + infinitive / past-like form with imperfective verbs

   • będzie zmieniać = will be changing / will change
   • będzie kończyć = will be ending

In your sentence, both key verbs are perfective, so Polish uses:

• zmieni
• skończy się

without a separate word meaning will.

It is in the accusative case because it is the direct object of zmienić (to change).

The tricky part is that for many masculine inanimate nouns, the accusative looks exactly the same as the nominative.

So:

• nominative: grafik
• accusative: grafik

That is why no visible ending change appears here.

Because dyżur is a masculine noun, so the possessive adjective must agree with it.

• mój = my (masculine)
• moja = my (feminine)
• moje = my (neuter)

So:

• mój dyżur = correct
• moja dyżur = incorrect

This is just adjective-noun agreement.

Dyżur usually means a shift, duty period, or sometimes on-call duty, depending on context.

It is often used for:

• doctors
• nurses
• emergency staff
• security staff
• people working assigned duty hours

In some situations, zmiana could also mean shift, but dyżur often suggests a scheduled period of duty or coverage.

So mój dyżur skończy się wcześniej means something like:

• my shift will end earlier
• my duty period will finish earlier

Because the verb here is skończyć się, which means to end / to come to an end.

The się is part of the verb’s meaning.

Compare:

• skończyć coś = to finish something
• skończyć się = to end / to be over

Examples:

• Skończę raport. = I’ll finish the report.
• Raport się skończy. = not natural for this meaning
• Dyżur skończy się wcześniej. = The shift will end earlier.

So in your sentence, the shift is not finishing something else; rather, it itself is ending.

For the same reason as zmieni: skończyć się is a perfective verb.

With perfective verbs, the non-past form usually refers to a future completed event.

So:

• skończy się = it will end
• not a normal present meaning like it ends right now

Polish perfective verbs generally do not have a true present meaning.

Because wcześniej is an adverb, and it modifies the verb phrase skończy się.

It answers the question how / when will it end?
→ earlier

• wcześniej = earlier
• wcześniejszy = earlier / earlier one, but as an adjective

Compare:

• Dyżur skończy się wcześniej. = The shift will end earlier.
  → adverb
• wcześniejszy dyżur = an earlier shift
  → adjective

So here the adverb is the correct choice.

Yes. Jeśli and jeżeli both mean if.

In most everyday contexts, they are interchangeable:

• Jeśli przełożona zmieni grafik...
• Jeżeli przełożona zmieni grafik...

Both are correct.

Very roughly:

• jeśli often sounds a bit more common and conversational
• jeżeli can sound slightly more formal or careful

But the difference is small.

Because Polish normally uses a comma to separate the conditional clause from the main clause.

So:

• Jeśli przełożona zmieni grafik, mój dyżur skończy się wcześniej.

The part before the comma is the if-clause.
The part after the comma is the result.

This is standard Polish punctuation.

Yes. Polish word order is fairly flexible, though some orders sound more neutral than others.

The given sentence is very natural:

• Jeśli przełożona zmieni grafik, mój dyżur skończy się wcześniej.

You could also say:

• Mój dyżur skończy się wcześniej, jeśli przełożona zmieni grafik.

That means the same thing:
My shift will end earlier if the supervisor changes the schedule.

The difference is mostly one of emphasis and information flow, not basic meaning.

It usually sounds like a real possible future condition:

• If the supervisor changes the schedule, my shift will end earlier.

This is not the same as an unreal/hypothetical English sentence like:

• If the supervisor changed the schedule, my shift would end earlier.

In Polish, that more hypothetical meaning would usually need different forms, often involving by:

• Gdyby przełożona zmieniła grafik, mój dyżur skończyłby się wcześniej.

So your original sentence is about a realistic possible future event.

Not only. Przełożona is broader than just boss.

Possible translations include:

• supervisor
• manager
• superior
• sometimes boss

The best English word depends on context. In a workplace schedule sentence, supervisor or manager is often the safest choice.

So learners should not assume there is always one single fixed English equivalent.