Posádka potřebuje vodáka.

Posádka means crew: a group of people in or operating a boat, vehicle, aircraft, etc.

In this sentence, because of vodáka, it most naturally sounds like a boat/rafting/canoeing crew.

A useful detail:

• posádka is a singular noun in Czech, even though it refers to several people, just like English crew.

Because posádka is grammatically singular.

So Czech treats it like this:

• posádka potřebuje = the crew needs

This is very similar to English:

• The crew needs help.

Even though the crew contains multiple people, the noun itself is singular, so the verb is singular too.

Potřebuje is the 3rd person singular present tense of potřebovat (to need).

So:

• já potřebuji / potřebuju = I need
• ty potřebuješ = you need
• on/ona/ono potřebuje = he/she/it needs
• my potřebujeme = we need
• vy potřebujete = you need
• oni potřebují = they need

Here it is potřebuje because the subject is posádka.

Vodák is a specifically Czech kind of word. It usually means a person who goes on the water recreationally, especially in things like:

• canoes
• kayaks
• rafts
• river boats

Depending on context, English translations might include:

• canoeist
• paddler
• boater
• sometimes rafter

It is not the usual word for sailor. For that, Czech would more likely use námořník.

Because vodáka is in the accusative case, which is used here for the direct object of the verb potřebuje.

The sentence structure is:

• Posádka = subject
• potřebuje = verb
• vodáka = direct object

The dictionary form is:

• vodák = nominative singular

But after a verb like need, Czech uses the accusative:

• vodáka = accusative singular

This happens because vodák is a masculine animate noun. For masculine animate nouns, the accusative singular often ends in -a:

• vodák → vodáka
• student → studenta
• muž → muže

They are:

• posádka = nominative singular
  • it is the subject of the sentence
• vodáka = accusative singular
  • it is the direct object

So the sentence is built very neatly as:

• Subject + Verb + Object
• Posádka potřebuje vodáka.

No. This is just grammatical gender, not biological sex.

In Czech, every noun has a grammatical gender. Posádka is feminine because that is how the noun behaves grammatically.

That does not mean:

• the crew is all women
• the crew is being described as female

It only affects grammar, such as adjective endings and past tense agreement.

Because Czech has no articles.

So vodáka could mean:

• a paddler
• the paddler

The exact meaning depends on context.

Likewise, posádka could be:

• a crew
• the crew

English requires articles, but Czech usually leaves that information to context.

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

The basic, neutral order here is:

• Posádka potřebuje vodáka.

But other orders are possible, depending on emphasis:

• Vodáka potřebuje posádka.

  • still means roughly The crew needs a paddler
  • but now vodáka is emphasized

• Potřebuje posádka vodáka?

  • Does the crew need a paddler?

So the original sentence is the most neutral way to say it, but it is not the only possible order.

A simple learner-friendly approximation is:

PO-saad-ka | PO-trzhe-boo-ye | VO-daa-ka

A few important pronunciation points:

• Czech stress is usually on the first syllable of each word.
• á is a long vowel, so say it a little longer:
  • posádka
  • vodáka
• potřebuje has four syllables:
  • po-tře-bu-je
• The sound ř is a special Czech sound with no exact English equivalent.
  • If you cannot say it yet, an approximate rzh-like sound is good enough at first.

So a careful pronunciation would be something like:

• PO-sá:d-ka PO-tře-bu-je VO-dá:-ka