Po pracy lubię odpoczywać na balkonie.

Because po requires a specific grammatical case here: the locative.

The base form is praca = work.
After po in the sense of after, it changes to pracy.

• praca → nominative
• pracy → locative

So:

• po pracy = after work

This is something you mostly have to learn with the preposition: po + locative in this meaning.

Usually it means after work in a general sense.

In this sentence, Po pracy lubię odpoczywać na balkonie means something like:

• After work, I like to relax on the balcony
• When work is over, I like to rest on the balcony

It does not specifically focus on the journey home. It just sets the time: once work is finished.

In Polish, the subject pronoun is often omitted because the verb ending already shows who is doing the action.

Here:

• lubię = I like

The ending -ę tells you it is I.

So:

• lubię odpoczywać = I like to rest
• ja lubię odpoczywać = also possible, but ja adds emphasis

You would use ja if you want contrast or emphasis, for example:

• Ja lubię odpoczywać, ale on woli spacerować.
  I like to rest, but he prefers to walk.

This is normal in Polish. The pattern is:

• lubić + infinitive = to like doing something

So:

• lubię czytać = I like reading / I like to read
• lubię gotować = I like cooking / I like to cook
• lubię odpoczywać = I like resting / I like to rest

The first verb is conjugated:

• lubię = I like

The second verb stays in the infinitive:

• odpoczywać = to rest, to relax

This is about aspect, which is very important in Polish.

• odpoczywać = imperfective
• odpocząć = perfective

In this sentence, the speaker is talking about a habit or a general preference, so Polish normally uses the imperfective:

• Lubię odpoczywać na balkonie.
  I like resting on the balcony.

The perfective odpocząć usually refers more to one completed instance of resting.

So for general likes and repeated activities, odpoczywać is the natural choice.

Because this sentence describes location, not movement.

Polish often uses:

• na + locative for being somewhere
• na + accusative for going onto/to somewhere

So:

• na balkonie = on the balcony / at the balcony area → location
• na balkon = onto the balcony → movement

Compare:

• Odpoczywam na balkonie.
  I am resting on the balcony.
• Idę na balkon.
  I am going out onto the balcony.

Because Polish idiomatically uses na with balkon.

So the normal phrase is:

• na balkonie = on the balcony

Even though English sometimes says on the balcony, this is not just literal logic in Polish; it is simply the standard preposition used with this noun.

Using w balkonie would sound wrong in this meaning.
W usually means in/inside, and a balcony is not thought of that way in Polish.

It is the locative singular of balkon.

Why locative? Because after na when it means in/on/at a place without movement, Polish uses the locative.

The forms are:

• balkon = base form
• na balkonie = on the balcony

So in this sentence:

• po pracy → locative after po
• na balkonie → locative after na for location

Yes. Polish word order is more flexible than English, although the basic meaning stays the same.

The original sentence:

• Po pracy lubię odpoczywać na balkonie.

Other possible orders include:

• Lubię odpoczywać na balkonie po pracy.
• Na balkonie lubię odpoczywać po pracy.

These versions may shift the focus slightly:

• Po pracy at the beginning emphasizes when
• Na balkonie at the beginning emphasizes where

The original sounds very natural and neutral.

No. It normally expresses a general habit or preference, not an action happening at this moment.

• Po pracy lubię odpoczywać na balkonie.
  = After work, I like to relax on the balcony.

It means this is something the speaker generally enjoys doing.

If you wanted to say it is happening right now, you would more likely say something like:

• Odpoczywam teraz na balkonie.
  I am resting on the balcony now.

Because Polish does not have articles like English a/an and the.

So:

• na balkonie can mean on the balcony
• po pracy can mean after work

Polish relies on context instead of articles.
This is very normal, and learners eventually get used to it.

A rough pronunciation guide is:

• od-po-CZY-wać

The stress is usually on the second-to-last syllable, so here it falls on czy.

A very rough English-style approximation would be:

• ot-po-CHI-vach

A few details:

• cz sounds like English ch in chop
• y is not exactly an English sound; it is a central vowel, a bit like a short, flatter i
• ć at the end of the infinitive spelling is not here; the ending is -wać, with ć absent because this verb ends in -wać

The whole sentence is pronounced roughly:

• Po PRA-cy LU-bye od-po-CZY-vach na bal-KO-nye

That is only an approximation, but it can help at the beginning.