Na końcu raportu dodaję jeszcze jeden przykład, bo bez niego temat nadal nie jest jasny.

Na końcu raportu means at the end of the report.

This is a fixed and very common Polish expression:

• na końcu = at the end
• na początku = at the beginning

By contrast, w końcu usually means finally, eventually, or after all, not a physical or textual end.

So:

• Na końcu raportu = at the end of the report
• W końcu dodałem przykład = I finally added an example

They are quite different in meaning.

Because after na końcu in this kind of phrase, Polish uses the genitive case.

So:

• raport = nominative, basic dictionary form
• raportu = genitive, meaning of the report

The phrase works like:

• na końcu raportu = at the end of the report
• literally: on the end of the report

Other similar examples:

• na końcu książki = at the end of the book
• na końcu filmu = at the end of the film

Dodaję is the 1st person singular present tense of dodawać.

So it means:

• I add
• or, depending on context, I am adding

In Polish, the present tense can often cover both a simple present and a present continuous meaning.

Here it sounds like:

• I’m adding one more example at the end of the report

The verb dodawać is imperfective, so it focuses on the process or action, not on completion. The perfective partner would be dodać.

Compare:

• dodaję = I add / I am adding
• dodam = I will add / I’ll add

Here jeszcze means something like still, yet, or most naturally one more / another when used with a numeral.

So:

• jeden przykład = one example
• jeszcze jeden przykład = one more example / another example

This is a very common pattern:

• jeszcze jeden raz = one more time
• jeszcze jedna kawa = one more coffee
• jeszcze jedno pytanie = one more question

So the phrase means:

• I add one more example

Because przykład is the direct object of dodaję, and for a masculine inanimate noun in the singular, the accusative form is the same as the nominative.

So:

• nominative: przykład
• accusative: przykład

That is why you see:

• dodaję przykład = I add an example

Compare this with a masculine animate noun, where accusative would be different:

• nominative: student
• accusative: studenta

Yes, ponieważ would also be possible.

• bo = because
• ponieważ = because / since

The difference is mostly one of style and register:

• bo is very common and natural in everyday speech and writing
• ponieważ sounds a bit more formal or written

So both are possible:

• ..., bo bez niego temat nadal nie jest jasny.
• ..., ponieważ bez niego temat nadal nie jest jasny.

In this sentence, bo sounds perfectly natural.

Bez niego means without it or without him, depending on what it refers to.

Here it refers to przykład (example), so the meaning is:

• without it

The form niego is used because the preposition bez requires the genitive case.

So:

• on = he
• niego = him / it, after certain prepositions and in genitive forms

With bez, you get:

• bez niego = without him / without it
• bez niej = without her / without it
• bez nich = without them

Even though przykład is not a person, Polish still uses the same pronoun form here.

Yes, temat literally means topic, but in many contexts it can also mean:

• subject
• issue
• matter

In this sentence, temat nadal nie jest jasny means something like:

• the topic is still not clear
• the issue is still not clear
• the matter is still unclear

So temat is broader than just a classroom “topic.” It often refers to the subject under discussion.

Both are possible, but nie jest jasny is very natural and common.

• jasny = clear
• nie jest jasny = is not clear
• niejasny = unclear

Polish often prefers:

• nie jest jasny over
• jest niejasny

The version with nie jest jasny can sound a bit more neutral and conversational.
Also, nadal means still, so:

• temat nadal nie jest jasny = the topic is still not clear

Because it agrees with temat.

• temat is masculine singular
• therefore the adjective is also masculine singular
• so we get jasny

This is standard adjective agreement in Polish.

Compare:

• temat jest jasny = the topic is clear
• sprawa jest jasna = the matter is clear
• pytanie jest jasne = the question is clear

The adjective changes according to the gender and number of the noun.

Yes, the comma is needed.

In Polish, bo introduces a subordinate clause explaining a reason, and it is normally preceded by a comma.

So this is correct:

• Na końcu raportu dodaję jeszcze jeden przykład, bo bez niego temat nadal nie jest jasny.

This is the same basic idea as in English when a reason clause is added after the main statement.

Yes. Polish word order is fairly flexible, but changing it changes the emphasis.

The given sentence is very natural:

• Na końcu raportu dodaję jeszcze jeden przykład, bo bez niego temat nadal nie jest jasny.

Other possible versions include:

• Dodaję jeszcze jeden przykład na końcu raportu, bo bez niego temat nadal nie jest jasny.
• Bo bez niego temat nadal nie jest jasny, na końcu raportu dodaję jeszcze jeden przykład.

But these sound different in focus. The original version emphasizes where the example is being added: at the end of the report.

So yes, the order can change, but the original is a very normal and well-balanced choice.