Kiedy wróciłem z oddziału, chciałem odpocząć, ale mężczyzna z mieszkania obok poprosił mnie o pomoc z terminalem.

These are past tense masculine singular forms.

• wróciłem = I returned / I came back (said by a man)
• chciałem = I wanted (said by a man)
• poprosił = he asked

Polish past tense agrees with gender and number.

If the speaker were female, you would say:

• wróciłam
• chciałam

If the man became a woman, it would be:

• poprosiła

So this sentence tells us:

• the speaker is male
• mężczyzna is also male, of course

In Polish, subject pronouns like ja (I) are often omitted because the verb ending already shows who is doing the action.

• wróciłem already means I returned
• chciałem already means I wanted

Adding ja is possible, but it usually adds emphasis or contrast:

• Ja chciałem odpocząć, ale on poprosił mnie o pomoc.
  = I wanted to rest, but he asked me for help.

So in normal narration, leaving out ja is completely natural.

Kiedy here means when.

It introduces a subordinate clause:

• Kiedy wróciłem z oddziału = When I came back from the ward/branch/department

Then the main clause follows:

• chciałem odpocząć = I wanted to rest

So the structure is:

• Kiedy... , ...
• When... , ...

This is very common in Polish.

Polish uses commas in places that are often similar to English here.

1. After the subordinate clause:

   • Kiedy wróciłem z oddziału, chciałem odpocząć...
   • The when-clause ends, so a comma separates it from the main clause.

2. Before ale:

   • ..., ale mężczyzna...
   • ale means but, and it normally takes a comma before it.

So both commas are required.

Oddział can mean several things depending on context, for example:

• ward (in a hospital)
• branch (of a bank or company)
• department/unit

The form oddziału is genitive singular.

That is because the preposition z in the sense of from/out of takes the genitive:

• z oddziału = from the ward/branch/department

Compare:

• oddział = nominative, basic dictionary form
• z oddziału = genitive after z

No, they do not mean exactly the same thing here.

1. z oddziału
   Here z means from/out of and takes the genitive:

   • z oddziału = from the ward/branch

2. z mieszkania obok
   Here z also means something like from, describing origin or association:

   • mężczyzna z mieszkania obok = the man from the apartment next door

3. z terminalem
   Here z means with, as in help with the terminal, and it takes the instrumental:

   • z terminalem = with the terminal

So the same preposition z can have different meanings and can govern different cases depending on context.

This is about aspect.

• odpocząć = perfective: to rest, to get some rest, to rest for a bit / to complete the act
• odpoczywać = imperfective: to be resting, to rest habitually, to spend time resting

After chciałem (I wanted), odpocząć sounds natural if the meaning is:

• I wanted to have a rest
• I wanted to rest a bit

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

• I wanted to be resting
• I wanted to spend time resting

In this sentence, odpocząć is the more natural choice.

Because poprosić kogoś means to ask someone.

The verb poprosić takes its person-object in the accusative:

• poprosił mnie = he asked me
• poprosił cię = he asked you
• poprosił go = he asked him

So:

• mnie is the accusative form of ja

This is different from English, where me is just the object form. In Polish, the case matters.

The pattern is:

• poprosić kogoś o coś = to ask someone for something

So:

• poprosił mnie o pomoc = he asked me for help

Here:

• mnie = the person being asked
• o pomoc = what he asked for

The preposition o here means for, and it takes the accusative.

That is why we have:

• pomoc in the accusative form

Yes — but only in function, not in appearance.

Pomoc is one of those nouns whose nominative and accusative singular look the same.

So:

• dictionary form: pomoc
• accusative after o: pomoc

That is why you see:

• o pomoc = for help

Even though the form does not visibly change, the case is still important grammatically.

Terminalem is instrumental singular of terminal.

• terminal = nominative
• terminalem = instrumental

In pomoc z terminalem, the phrase means:

• help with the terminal

The z + instrumental pattern often means with in the sense of being connected to something.

So:

• poprosił mnie o pomoc z terminalem = he asked me for help with the terminal

You may also hear other Polish ways to express this idea, such as:

• o pomoc przy terminalu
• o pomoc w obsłudze terminala

But the sentence as given is understandable and natural in everyday usage.

Because after z meaning from, Polish uses the genitive, not the instrumental.

So:

• mieszkanie = apartment/flat
• z mieszkania = from the apartment

Therefore:

• mężczyzna z mieszkania obok = the man from the apartment next door

By contrast:

• z mieszkaniem would use the instrumental and would mean something more like with an apartment, which is not the meaning here.

Obok means next to / beside / nearby.

In this sentence:

• z mieszkania obok

it means something like:

• from the apartment next door
• from the neighboring apartment

So obok helps describe which apartment we mean.

A very close alternative would be:

• z sąsiedniego mieszkania = from the neighboring apartment

This is another aspect difference.

• wróciłem = perfective
  I came back / I returned
  Focus on the completed return.

• wracałem = imperfective
  I was coming back / I used to come back / I was on my way back
  Focus on the process or repeated action.

In this sentence, wróciłem is used because the speaker had already completed the return:

• When I came back from the ward/branch, I wanted to rest...

If you used wracałem, it would suggest an ongoing action and would likely change the meaning.

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

The original sentence is neutral and natural:

• Kiedy wróciłem z oddziału, chciałem odpocząć, ale mężczyzna z mieszkania obok poprosił mnie o pomoc z terminalem.

You could move parts around for emphasis, for example:

• Kiedy wróciłem z oddziału, ale mężczyzna z mieszkania obok poprosił mnie o pomoc z terminalem, chciałem odpocząć.
  This sounds awkward and is not a good choice.

Or:

• Mężczyzna z mieszkania obok poprosił mnie o pomoc z terminalem, kiedy wróciłem z oddziału.
  Possible, but the focus shifts.

So yes, word order can change, but the original version is the most straightforward and natural for narration.

Because the sentence expresses contrast.

• chciałem odpocząć = I wanted to rest
• ale = but
• mężczyzna... poprosił mnie o pomoc = the man asked me for help

So the idea is:

• I wanted to rest, but something happened that prevented or interrupted that.

If you used:

• i = and
  It would just add information, without contrast.

• więc = so
  That would suggest a result, which is not the intended meaning.

So ale is the correct conjunction here.