Nasz zawodnik lubi strzelać bramki.

Because nasz has to agree with zawodnik in gender, number, and case.

• zawodnik is masculine singular
• here it is in the nominative case, because it is the subject of the sentence

So the correct form is nasz zawodnik.

Compare:

• nasza zawodniczka = our female athlete
• nasze dziecko = our child
• nasi zawodnicy = our athletes

It is in the nominative singular.

In this sentence, zawodnik is the subject: the person who likes doing something. Subjects are normally in the nominative case in Polish.

Lubić is the dictionary form of the verb, meaning to like.

In the sentence, we need a conjugated form:

• ja lubię = I like
• ty lubisz = you like
• on/ona/ono lubi = he/she/it likes

Since nasz zawodnik is he/the player, we use lubi.

After lubić, Polish usually uses an infinitive to say what someone likes doing.

So:

• lubi strzelać = likes to score / likes scoring
• lubi biegać = likes to run
• lubi czytać = likes to read

This is very natural in Polish and works a lot like English likes to... or likes ...-ing.

This is a question of aspect, which is very important in Polish.

• strzelać = imperfective
• strzelić = perfective

Here, strzelać is used because the sentence talks about a general habit or preference: the player likes scoring goals.

Very roughly:

• lubi strzelać bramki = he likes scoring goals in general
• strzelił bramkę = he scored a goal / he managed to score one completed goal

After lubić, the imperfective verb is usually the natural choice when talking about activities someone enjoys.

Because bramki is plural.

• bramkę = one goal, accusative singular
• bramki = goals, accusative plural

In this sentence, the meaning is general: he likes scoring goals, not just one goal.

Also, bramki is the direct object of strzelać, so it is in the accusative case. For many feminine nouns in the plural, the accusative plural looks the same as the nominative plural, which is why you see bramki.

Grammatically, yes, but it would sound less natural in this context.

• strzelać bramki = to score goals, in general
• strzelać bramkę = to score a goal

Since lubi expresses a general liking or repeated activity, the plural bramki sounds more natural here.

Yes. Strzelać gole is also natural Polish.

Both are common in sports language:

• strzelać bramki
• strzelać gole

They are very close in meaning here. A learner will hear both.

No, Polish word order is fairly flexible, because case endings help show what each word is doing.

The neutral, most straightforward order is:

• Nasz zawodnik lubi strzelać bramki.

But other orders are possible for emphasis, for example:

• Bramki lubi strzelać nasz zawodnik.
• Strzelać bramki lubi nasz zawodnik.

These alternatives change the focus or emphasis, not the basic meaning.

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

So nasz zawodnik can mean:

• our player
• our athlete

English has to choose an article or leave it out depending on context, but Polish does not.

Usually, zawodnik is the masculine word, so it normally refers to a male athlete or competitor.

For a female athlete, Polish usually uses:

• zawodniczka

So:

• Nasz zawodnik lubi strzelać bramki. = our male player likes scoring goals
• Nasza zawodniczka lubi strzelać bramki. = our female player likes scoring goals

A rough guide is: stzhe-lach.

A few useful pronunciation points:

• rz sounds like the s in measure
• ć is a soft sound, a bit like a very soft ch in cheese
• the whole word is pronounced approximately STRZE-lać, with the stress on the second-to-last syllable: strze-LAĆ

If you want a more exact version, the IPA is /ˈstʂɛlat͡ɕ/.