Piłkarz słucha trenera na stadionie.

The subject is piłkarz.

It is in the nominative case, which is the normal case for the doer of the action. In this sentence, piłkarz is the person doing the listening.

So:

• piłkarz = the footballer / soccer player
• słucha = listens / is listening
• trenera = the coach
• na stadionie = at the stadium / in the stadium

Because the verb słuchać takes the genitive case, not the accusative.

A learner might expect something like Piłkarz słucha trenera to work like English The footballer listens to the coach, where coach looks unchanged. In Polish, however, many verbs require a specific case, and słuchać is one of the verbs that requires genitive.

So:

• base form: trener = coach
• genitive singular: trenera

That is why the sentence uses trenera.

This is something you mostly have to learn together with the verb:

• słuchać kogo? czego? = to listen to whom? to what?

Here na stadionie is in the locative case.

The preposition na can take different cases depending on meaning:

• na + accusative = movement toward a place
  
  • Idę na stadion. = I am going to the stadium.
• na + locative = being at a place
  
  • Jestem na stadionie. = I am at the stadium.

In your sentence, the action happens at that location, so Polish uses the locative:

• stadion → stadionie

So na stadionie means at the stadium or in the stadium, depending on context.

Usually it can mean either, depending on context.

In English, at the stadium often focuses on the general location, while in the stadium can sound more physically inside it. Polish na stadionie commonly covers both ideas.

So this phrase is very natural for:

• being present at the stadium
• being somewhere in the stadium area
• the action taking place there

Polish often uses na with places like this where English learners might expect in.

Yes. Polish word order is more flexible than English because case endings show grammatical roles.

The neutral order here is:

• Piłkarz słucha trenera na stadionie.

But you could also say:

• Na stadionie piłkarz słucha trenera.
• Trenera słucha piłkarz na stadionie.

These versions are grammatical, but they change the focus or emphasis.

For example:

• Na stadionie piłkarz słucha trenera.
  emphasizes the location: At the stadium, the footballer listens to the coach.

Even with changed order, piłkarz is still the subject and trenera is still the object because their case forms show their roles.

A little, yes.

Grammatically, na stadionie modifies the whole situation, so the most natural reading is:

• the listening happens at the stadium

In normal usage, that strongly suggests the footballer is at the stadium, and probably the coach too. But the phrase itself does not spell out exactly which person the location belongs to.

If you wanted to make things more explicit, you would usually add more context.

Because Polish does not have articles.

English uses articles:

• a footballer
• the footballer

Polish usually leaves that distinction to context. So piłkarz can mean:

• a footballer
• the footballer

The same is true for trenera:

• a coach
• the coach

You understand which one is meant from the situation, previous sentences, or emphasis.

Roughly, piłkarz sounds like peew-kash, but that is only an approximation.

A few useful points:

• pił-: the ł sounds like English w
• rz often sounds like the zh sound in measure
• in piłkarz, many learners hear the end roughly like kash or karzh, depending on speech

Also:

• słucha starts with sł, where ł again sounds like w
• so słucha sounds roughly like SWOO-ha or SWOO-kha, with a throaty ch

The Polish ch is not like English ch in chair. It is more like the ch in Scottish loch or German Bach.

Słucha is the 3rd person singular present tense form of słuchać.

The subject piłkarz is singular, so the verb must also be singular:

• ja słucham = I listen
• ty słuchasz = you listen
• on/ona słucha = he/she listens

So:

• Piłkarz słucha = The footballer listens / is listening

Polish present tense can often translate as either simple present or present continuous in English, depending on context.

Not if you want the same meaning.

There is an important difference:

• słuchać = to listen
  
  • active, intentional
• słyszeć = to hear
  
  • passive, simply perceiving sound

So:

• Piłkarz słucha trenera. = The footballer is listening to the coach.
• Piłkarz słyszy trenera. = The footballer hears the coach.

In your sentence, słucha is correct because the player is paying attention to the coach.

The dictionary forms are:

• piłkarz → piłkarz
• słucha → słuchać
• trenera → trener
• stadionie → stadion

This is useful because Polish words often change their endings depending on case, number, or verb conjugation. When you learn vocabulary, you usually learn the dictionary form first and then the patterns for changing it.