Raport jest już zrobiony, więc mogę odpocząć.

Because raport is the subject of the sentence, so it stays in the nominative case.

• raport = the report
• jest zrobiony = is done

So the structure is basically:

• Raport = subject
• jest już zrobiony = predicate

If you changed the role of the word in the sentence, the case could change too, for example:

• Nie ma raportu. = There is no report.
• Zajmuję się raportem. = I am dealing with the report.

Jest is the present tense of być (to be), so jest zrobiony literally means is done.

In English, you also normally need is in a sentence like The report is done. Polish works similarly here.

That said, in everyday Polish, people sometimes drop jest in informal speech if the meaning is obvious:

• Raport już zrobiony.

This sounds more casual or shortened, like Report’s already done in English. But the full standard sentence is:

• Raport jest już zrobiony.

Zrobiony is a past passive participle, formed from the verb zrobić (to do / to make / to complete).

In this sentence, it behaves a lot like an adjective and agrees with raport:

• raport is masculine singular
• so we use zrobiony

Compare:

• raport jest zrobiony = the report is done
• praca jest zrobiona = the work is done
• zadanie jest zrobione = the task is done
• raporty są zrobione = the reports are done

So the ending changes depending on the noun.

Because raport is a masculine singular noun.

The participle must agree with the noun in gender and number:

• masculine singular: zrobiony
• feminine singular: zrobiona
• neuter singular: zrobione
• non-masculine-personal plural: zrobione
• masculine-personal plural: zrobieni

Examples:

• Raport jest zrobiony.
• Lista jest zrobiona.
• Zadanie jest zrobione.
• Dokumenty są zrobione.

Już means already.

It tells us that the action has been completed by now or sooner than expected / at this point:

• Raport jest zrobiony. = The report is done.
• Raport jest już zrobiony. = The report is already done.

So już adds the idea of completion at this moment.

It is a very common word in Polish and often appears near the verb or the predicate.

Yes, Polish word order is more flexible than English, but some positions sound more neutral than others.

The most natural neutral version here is:

• Raport jest już zrobiony.

You may also hear:

• Już raport jest zrobiony.
• Raport już jest zrobiony.

These are possible, but they shift emphasis a bit.

Very roughly:

• Raport jest już zrobiony. = neutral, standard
• Raport już jest zrobiony. = slightly more emphasis on already
• Już raport jest zrobiony. = more marked, depending on context

For learners, the safest choice is the original sentence.

Więc means so, therefore, or thus.

It connects the two parts of the sentence:

• Raport jest już zrobiony = The report is already done
• więc mogę odpocząć = so I can rest

In Polish, a comma is normally used before conjunctions like więc when they connect clauses.

So:

• Raport jest już zrobiony, więc mogę odpocząć.

This punctuation is standard and correct.

Mogę is the 1st person singular present tense of móc (can / to be able to).

So:

• mogę = I can

After móc, Polish uses the infinitive of the second verb:

• mogę odpocząć = I can rest

This is similar to English:

• I can rest

Other examples:

• Mogę iść. = I can go.
• Mogę zacząć. = I can begin.
• Mogę pracować. = I can work.

This is a question of aspect.

Polish verbs often come in pairs:

• odpoczywać = imperfective
• odpocząć = perfective

Here, odpocząć is used because it means to have a rest / to rest for a while and complete that rest as a single whole action.

So:

• mogę odpocząć = I can have a rest / I can rest now

If you said mogę odpoczywać, it would sound more like:

• I can be resting
• I can rest in an ongoing way

That is possible in some contexts, but mogę odpocząć is much more natural here.

Yes, zrobić is a perfective verb.

Its imperfective partner is usually:

• robić = to do, to be doing
• zrobić = to do, to complete, to get done

In zrobiony, the idea is that the report has been completed, not just worked on. That matches the perfective verb zrobić very well.

Compare:

• robić raport = to work on / do a report
• zrobić raport = to complete the report

So zrobiony strongly suggests a finished result.

Yes, you can. It would mean something like The report is already finished.

Compare:

• Raport jest już zrobiony. = The report is already done.
• Raport jest już skończony. = The report is already finished.

Both are natural. The difference is small:

• zrobiony focuses more on having done / completed the task
• skończony focuses more on being finished

In many everyday situations, they are interchangeable.

It is close to what English speakers think of as a passive-like structure, but in Polish it is often best understood as być + participle, describing a resulting state.

• Raport jest zrobiony = The report is done.

If you wanted to mention the person who did it, Polish usually avoids a direct English-style passive with by unless needed. Often people simply say something more active, for example:

• Zrobiłem już raport. = I’ve already done the report.

So for learners, it is useful to think of jest zrobiony as is done / has been done, depending on context.

In this sentence, usually no, because raport is the thing being talked about, and it is not contained in the verb ending.

Polish often omits personal pronouns because verb endings show the person:

• Mogę odpocząć. = I can rest.
  (No need to say ja unless you want emphasis.)

But with a noun like raport, you normally keep it unless the context already makes it obvious and you are continuing a conversation.

For example:

• Raport jest już zrobiony. Mogę odpocząć.

In the second sentence, I is omitted, but raport was needed in the first one.

A simple learner-friendly pronunciation is:

• mogę ≈ MOH-gheh with a nasalized ending

The letter ę is a nasal vowel, but in real speech its pronunciation changes depending on the sound that follows.

At the end of a word, many speakers pronounce ę less strongly nasal than learners expect. So mogę may sound somewhat like:

• moge
• or lightly nasalized mogę

You do not need to overdo the nasal sound. A natural pronunciation matters more than making it extremely nasal.

Also remember the stress:

• MO-gę
• od-PO-cząć
• RA-port

Polish stress is usually on the second-to-last syllable.

To some extent, yes. Polish word order is flexible, but different orders change emphasis.

Neutral:

• Raport jest już zrobiony, więc mogę odpocząć.

Possible alternatives:

• Już raport jest zrobiony, więc mogę odpocząć.
• Raport już jest zrobiony, więc mogę odpocząć.
• Mogę odpocząć, bo raport jest już zrobiony.

These all express a similar basic idea, but the original version is the most natural, neutral one for a learner to copy.

So the best advice is:

• understand that word order can move,
• but use the original order until you get more comfortable with Polish emphasis patterns.