Po meczu trener powiedział piłkarzowi i piłkarce, że dobrze bronili i długo walczyli.

Because the preposition po usually takes the locative case when it means after in a time sense.

• mecz = match
• po meczu = after the match

So mecz changes to meczu because it is in the locative singular.

A few similar examples:

• po obiedzie = after dinner
• po pracy = after work
• po filmie = after the film

Because the verb powiedzieć often works with the pattern:

• powiedzieć komuś coś / że...
  = to say/tell someone something / that...

So the person receiving the message goes into the dative case.

Here:

• piłkarz → piłkarzowi = to the male footballer
• piłkarka → piłkarce = to the female footballer

So:

• trener powiedział piłkarzowi i piłkarce
  = the coach told the male footballer and the female footballer

They are both in the dative singular.

This is because they are the indirect objects of powiedział.

Breakdown:

• piłkarz → nominative singular

• piłkarzowi → dative singular

• piłkarka → nominative singular
• piłkarce → dative singular

In English, we usually express this with to:

• powiedział piłkarzowi = said to the footballer

Even though English often does not mark this with a special ending, Polish does.

Because powiedział agrees with the subject, not with the people being spoken to.

The subject here is:

• trener = the coach

Since trener is singular masculine, the verb is also singular masculine past:

• trener powiedział = the coach said

The two players are not the subject of powiedział. They are the people the coach spoke to.

Because these verbs refer to piłkarzowi i piłkarce together — the male footballer and the female footballer.

So inside the clause after że, the implied subject is they.

• że dobrze bronili i długo walczyli
• that they defended well and fought for a long time

Since two people are being talked about, the verbs are in the plural past tense.

Because in Polish, a group containing at least one male person normally takes the masculine personal plural form.

Here the group is:

• one man: piłkarz
• one woman: piłkarka

So the correct plural past form is masculine personal:

• bronili
• walczyli

If the group were all female, you would use:

• broniły
• walczyły

For example:

• Piłkarki dobrze broniły. = The female footballers defended well.

But with a mixed group, Polish uses the masculine personal plural.

Że means that and introduces a subordinate clause.

So:

• trener powiedział ..., że...
• the coach said ..., that...

In English, that is often optional:

• The coach said that they defended well.
• The coach said they defended well.

In Polish, że is normally stated explicitly in this kind of sentence.

They are adverbs, because they describe how the actions were done.

• dobrze bronili = they defended well
• długo walczyli = they fought for a long time / they kept fighting a long time

They modify the verbs:

• bronić = to defend
• walczyć = to fight

Not the nouns.

This is why you do not use adjective forms here.

Because the sentence describes actions as ongoing or extended during the match, not as single completed events.

• bronić is imperfective
• walczyć is imperfective

That fits the meaning well:

• they were defending well
• they fought for a long time / kept fighting

Imperfective verbs are very common when describing:

• duration
• repeated effort
• process
• general performance

A perfective verb would suggest a more bounded, completed event, which is not the point here.

Yes. Powiedzieć is the perfective partner of mówić in many contexts.

• mówić = to speak / to say, imperfective
• powiedzieć = to say / to tell, perfective

Here, the coach made one completed statement after the match, so powiedział fits naturally.

• Po meczu trener powiedział...
• After the match, the coach said...

If you used mówił, it would usually suggest something more ongoing, repeated, or backgrounded:

• Po meczu trener mówił, że...
• After the match, the coach was saying / said repeatedly that...

So powiedział is the more natural choice for one finished act of speaking.

Because Polish often omits subject pronouns when they are clear from context.

Here, after piłkarzowi i piłkarce, it is clear that the next clause refers to those two people.

So Polish does not need to say:

• że oni dobrze bronili...

It can simply say:

• że dobrze bronili...

The verb ending and the context already tell you the subject is plural.

This is very normal in Polish.

Yes. Polish word order is fairly flexible, although some orders sound more neutral than others.

The original sentence is natural:

• Po meczu trener powiedział piłkarzowi i piłkarce, że dobrze bronili i długo walczyli.

But you could also say, for example:

• Trener po meczu powiedział piłkarzowi i piłkarce, że dobrze bronili i długo walczyli.

The meaning stays basically the same. The difference is mainly in emphasis or style.

Still, the original order sounds very normal and neutral.

Yes, depending on how you phrase it in English.

Polish often uses powiedzieć komuś, że..., which can correspond to either:

• said to someone that...
• told someone that...

So this sentence could be understood as:

• The coach said to the male footballer and the female footballer that...
• The coach told the male footballer and the female footballer that...

In natural English, told is often more likely here because there is a clear recipient.

Yes. In this sentence, both nouns are singular:

• piłkarzowi = to a male footballer
• piłkarce = to a female footballer

Together they mean exactly two people:

• one man
• one woman

That is why the later verb forms are plural.

If it were more than one male footballer and more than one female footballer, the forms would be different.

From the grammar and the context.

The sentence structure is:

• After the match, the coach told the male footballer and the female footballer that [they] defended well and fought for a long time.

The most natural interpretation is that bronili and walczyli refer to the two players mentioned just before że.

Also, the plural masculine-personal ending -li matches a mixed male-female pair.

So the sentence means the coach praised those two players for their performance.

Yes. In this context, bronić means to defend, especially in a sports sense.

So:

• dobrze bronili = they defended well

This is a very natural use in football/soccer language.

Depending on context, bronić can also mean things like:

• to protect
• to defend someone/something
• to defend an idea or position

But in this sentence, the sports meaning is clearly intended.