Po pracy zagram na gitarze.

Because the preposition po in the sense of after requires the locative case in Polish.

• praca = work
• locative singular: pracy

So:

• po pracy = after work

This is a very common pattern:

• po obiedzie = after dinner
• po szkole = after school
• po zajęciach = after classes

Be careful: po can take different cases in other meanings, but in this time meaning (after), you usually use the locative.

Zagram means I will play.

It comes from the verb zagrać, which is a perfective verb. In Polish, perfective verbs often use present-tense endings to express the future.

So:

• zagram = I will play
• zagrasz = you will play
• zagra = he/she/it will play

Even though the form looks like a present-tense form, its meaning is future because zagrać is perfective.

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

• zagrać / zagram = perfective
  This suggests a single, complete action: I’ll play / I’ll have a go at playing
• grać / będę grać, będę grał/grała = imperfective
  This focuses more on the activity itself, duration, or repetition: I’ll be playing

So:

• Po pracy zagram na gitarze.
  = After work, I’ll play the guitar.
  This sounds like one planned action.

Compare:

• Po pracy będę grał na gitarze. / będę grała na gitarze.
  = After work, I’ll be playing the guitar.
  This stresses the ongoing activity more.

Both are possible, but zagram is very natural for a simple plan.

Because in Polish, when you talk about playing a musical instrument, the usual structure is:

grać na + locative

So:

• grać na gitarze = to play the guitar
• grać na pianinie = to play the piano
• grać na skrzypcach = to play the violin

That is just the normal Polish pattern. It does not match English word-for-word.

Here:

• gitara = guitar
• locative singular: gitarze

So:

• na gitarze = on the guitar / guitar-playing

Because Polish usually drops subject pronouns when they are obvious from the verb form.

• zagram already means I will play

So ja is not necessary.

You could say:

• Ja po pracy zagram na gitarze.

But that would usually add emphasis, like:

• I’ll play the guitar after work
• As for me, I’ll play the guitar after work

In neutral sentences, Polish normally leaves out ja.

Yes. In normal speech, po pracy often means:

• after work
• after I finish work
• after the workday
• after work hours

The exact nuance depends on context. Polish often leaves this slightly general, just like English does with after work.

Yes. Polish word order is more flexible than English word order.

The neutral version here is:

• Po pracy zagram na gitarze.

But you could also say:

• Zagram na gitarze po pracy.
• Na gitarze zagram po pracy.

These all mean roughly the same thing, but the emphasis changes.

For example:

• Po pracy zagram na gitarze.
  neutral, natural
• Zagram na gitarze po pracy.
  slightly more emphasis on I’ll play
• Na gitarze zagram po pracy.
  stronger emphasis on on the guitar

So yes, the sentence can be reordered, but some versions sound more natural than others depending on context.

Gitarze is in the locative singular.

The base form is:

• gitara = guitar

After na in this expression (grać na gitarze), Polish uses the locative:

• na gitarze

So in this sentence you have two locatives:

• po pracy — locative after po
• na gitarze — locative after na in this fixed expression

Grammatically, it is built like play on the guitar, but in meaning it simply corresponds to English play the guitar.

This is a good example of where Polish and English use different grammar patterns for the same idea.

So you should learn it as a chunk:

• grać na gitarze = play the guitar

Not as a literal word-for-word translation.

The dictionary form is zagrać.

That is the perfective infinitive meaning to play (as a completed/single action in the right context).

Its imperfective partner is:

• grać = to play

This pair is useful to remember:

• grać — imperfective
• zagrać — perfective

Then you would use the imperfective future:

• Po pracy będę grała na gitarze.

If you are male:

• Po pracy będę grał na gitarze.

This is different from zagram:

• zagram = I will play
• będę grał/grała = I will be playing / I will play

The second version shows gender in the past-like participle:

• grał = male speaker
• grała = female speaker

But zagram does not show gender.

Yes, definitely. Po pracy is a very common everyday phrase.

It is useful to memorize it as a chunk:

• po pracy = after work

You can then use it in many sentences:

• Po pracy idę do domu. = After work I’m going home.
• Po pracy spotkam się z kolegą. = After work I’ll meet a friend/colleague.
• Po pracy jestem zmęczony / zmęczona. = After work I’m tired.

Learning common preposition + noun combinations as chunks is very helpful in Polish.

Yes. In everyday English, I’ll play the guitar after work often just means I’ll spend some time playing guitar, and Polish Po pracy zagram na gitarze can work the same way.

It does not have to mean a concert or a serious performance. Very often it just means a normal activity you plan to do after work.