Kapitan i drużyna muszą się naradzić przed rundą bez podpowiedzi.

Because the subject is Kapitan i drużyna — two elements joined by i (and). In Polish, that makes the subject plural, so the verb must also be plural: muszą.

Compare:

• Kapitan musi — The captain must
• Drużyna musi — The team must
• Kapitan i drużyna muszą — The captain and the team must

Naradzić się is a verb meaning to confer, to consult together, or to talk something over and reach a decision. The się is part of the verb itself; it is not a separate word meaning themselves in a literal English sense.

A lot of Polish verbs are built with się, and you often just have to learn them that way. Here, naradzić się is the dictionary form of the verb.

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

• naradzić się = perfective
• naradzać się = imperfective

With muszą się naradzić, the idea is that they need to have the discussion and complete it before the round starts. It refers to one whole, completed act.

If you said muszą się naradzać, it would suggest an ongoing or repeated process, not so clearly one completed consultation before the round.

In neutral Polish, się often appears before the infinitive, so muszą się naradzić is very natural.

You may also hear muszą naradzić się, but that is usually less neutral and can sound slightly marked or stylistically different. For a learner, muszą się naradzić is the safest and most standard order.

Because the preposition przed requires the instrumental case in this meaning. The noun runda changes to instrumental singular rundą.

So:

• runda = basic form
• przed rundą = before the round

This is a very common pattern in Polish: prepositions often force a specific case.

After bez (without), Polish uses the genitive case. So podpowiedź changes to podpowiedzi.

That means:

• podpowiedź = basic form
• bez podpowiedzi = without a hint / without hints / without prompting

The form podpowiedzi happens to look the same as some other Polish forms, but after bez, you know it must be genitive.

Grammatically, drużyna is singular. It means team, which is a group, but Polish treats it as one singular noun.

So by itself you would say:

• Drużyna musi — The team must

In the sentence Kapitan i drużyna muszą..., the whole subject becomes plural because it includes both the captain and the team.

Polish does not have articles like English a/an and the. Nouns such as kapitan, drużyna, and runda can be understood as a or the depending on context.

So Polish leaves that information to context instead of marking it with separate words.

Yes. Polish word order is more flexible than English because case endings and verb forms show the grammatical relationships.

The given sentence is natural and neutral:

• Kapitan i drużyna muszą się naradzić przed rundą bez podpowiedzi.

But you could also say:

• Przed rundą kapitan i drużyna muszą się naradzić.
• Kapitan i drużyna przed rundą muszą się naradzić.

These versions are still correct; they just shift emphasis slightly.

They are in the nominative case because they form the subject of the sentence.

The nominative is the basic dictionary form used for the doer of the action:

• kapitan
• drużyna

That is why these two nouns do not change form here, while runda and podpowiedź do change after their prepositions.