Ostatní jsou s vítězem.

Here ostatní means the others or the rest.

It is being used as a plural noun-like adjective: literally something like the remaining ones. Czech often uses adjectives this way.

So in this sentence:

• ostatní = the others
• jsou = are
• s vítězem = with the winner

Jsou is the 3rd person plural form of být (to be).

Because ostatní refers to more than one person, Czech uses the plural verb:

• je = is
• jsou = are

So:

• Ostatní je... would be wrong here
• Ostatní jsou... = The others are...

The preposition s meaning with requires the instrumental case in Czech.

The basic form is:

• vítěz = winner

But after s, it changes to instrumental:

• s vítězem = with the winner

So this is not a random ending — it is required by the preposition s.

Vítězem is in the instrumental singular.

For masculine nouns like vítěz, the instrumental singular often ends in -em.

So:

• nominative: vítěz
• instrumental: vítězem

Because the sentence uses s (with), Czech needs the instrumental: s vítězem.

Because they play different roles in the sentence.

• ostatní is the subject of the sentence, so it stays in the nominative
• vítězem comes after s, so it must be in the instrumental

So the sentence structure is:

• Ostatní = subject, nominative
• jsou = verb
• s vítězem = prepositional phrase, instrumental after s

Grammatically, ostatní is originally an adjective meaning remaining or other, but here it is used substantively, meaning it functions like a noun.

That is very common in Czech.

Compare:

• ostatní lidé = the other people / the remaining people
• ostatní = the others

So in this sentence, ostatní means the others without needing to say the noun explicitly.

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

The neutral order here is:

• Ostatní jsou s vítězem.

But you might also see:

• S vítězem jsou ostatní.
• S vítězem ostatní jsou. — possible, but less neutral and more marked

Changing the order usually changes emphasis, not the basic meaning.

The given sentence sounds neutral and natural.

Not always, but very often.

In this sentence, s clearly means with:

• s vítězem = with the winner

However, in some contexts s can also mean something like together with or be part of other expressions.

A useful thing to remember is:

• when s means with, it takes the instrumental case

Also note that Czech has both s and z/ze, and English speakers sometimes confuse them:

• s = with
• z = from / out of

A rough pronunciation guide is:

Ostatní jsou s vítězem
≈ oh-staht-nee zsoh s vee-tye-zem

A few useful points:

• í is a long vowel
• jsou is pronounced roughly like zsoh
• tě sounds approximately like tye
• ř is not in this sentence, so there is nothing especially difficult there by Czech standards

Stress in Czech usually falls on the first syllable of each word:

• OStatní
• JSOU
• S
• VÍtězem

No. Czech does not have articles like English the and a/an.

So:

• ostatní can mean the others
• vítěz can mean a winner or the winner
• vítězem can mean with a winner or with the winner

The exact meaning depends on context. If the meaning shown to you is The others are with the winner, that comes from the context, not from an article.

Possibly, depending on context, but literally it means The others are with the winner.

In Czech, být s někým can sometimes imply:

• physical presence: to be with someone
• social or emotional alignment: to be on someone’s side

So if the context is political, competitive, or emotional, it could suggest support or standing by the winner. But the basic literal structure is still are with the winner.

The dictionary forms are:

• ostatní — this form itself is also the dictionary form
• být — to be; the sentence uses jsou
• s — with
• vítěz — winner; the sentence uses vítězem

So if you were looking the words up, you would search for:

• ostatní
• být
• s
• vítěz

Yes. Vítěz is a masculine animate noun.

That matters because masculine animate nouns often have their own case patterns.

Here the singular forms are:

• nominative: vítěz
• instrumental: vítězem

If the noun were plural, it would change differently:

• s vítězi = with the winners

So vítězem tells you it is singular instrumental.