Sam film jest ciekawy, ale zakończenie jest smutne.

Here sam means the film itself or the film alone. It adds emphasis.

So:

• film jest ciekawy = the film is interesting
• sam film jest ciekawy = the film itself is interesting

It suggests a contrast, which fits the second part of the sentence:

• Sam film jest ciekawy, ale zakończenie jest smutne.
• The film itself is interesting, but the ending is sad.

In other words, the movie as a whole or in general may be interesting, but one specific part—the ending—is sad.

Because sam has to agree with film in gender, number, and case.

Film is:

• masculine
• singular
• nominative

So the correct form is:

• sam = masculine singular nominative

Other forms would be used with different nouns:

• sama książka = the book itself (książka is feminine)
• samo dziecko = the child itself (dziecko is neuter)
• same filmy = the films themselves (plural)

So sam film is correct because film is a masculine singular noun.

Because adjectives in Polish must agree with the noun they describe.

In this sentence:

• film is masculine singular, so we get ciekawy
• zakończenie is neuter singular, so we get smutne

Breakdown:

• film jest ciekawy = the film is interesting
• zakończenie jest smutne = the ending is sad

This is a very important rule in Polish: adjective endings change depending on the noun.

For comparison:

• ciekawy film = an interesting film
• ciekawa książka = an interesting book
• ciekawe zakończenie = an interesting ending

Zakończenie is neuter.

A very common clue is the ending -e or -o in the singular nominative, especially for nouns like:

• dziecko = child
• okno = window
• zakończenie = ending

Also, many Polish nouns ending in -enie, -anie, or -cie are neuter verbal nouns, such as:

• jedzenie = food / eating
• pytanie = question
• zakończenie = ending / conclusion

Because it is neuter, the adjective is also neuter:

• smutne zakończenie
• zakończenie jest smutne

Both are in the nominative case.

Why?

Because they are the subjects of the two clauses:

• Sam film jest ciekawy
• zakończenie jest smutne

In Polish, after jest with this kind of adjective predicate, the subject stays in the nominative:

• Film jest ciekawy
• Książka jest dobra
• Zakończenie jest smutne

The adjectives ciekawy and smutne also match the subject in nominative form.

Because the sentence has two separate clauses, each with its own subject and predicate:

1. Sam film jest ciekawy
2. ale zakończenie jest smutne

Each clause needs its own jest in normal standard Polish.

You may sometimes see omission of jest in very informal speech, notes, headlines, or stylistic writing, but in ordinary correct sentences like this, keeping jest is natural and expected.

So this sentence is perfectly standard:

• Sam film jest ciekawy, ale zakończenie jest smutne.

Yes, Polish word order is fairly flexible, but changing it changes the emphasis.

The given sentence:

• Sam film jest ciekawy, ale zakończenie jest smutne.

puts emphasis on sam film = the film itself.

You could also hear variations like:

• Film sam jest ciekawy, ale zakończenie jest smutne.
• Ciekawy jest sam film, ale zakończenie jest smutne.

These are possible, but they sound more marked or stylistically shaped. For a learner, the original version is the most natural and easiest to use.

Here zakończenie means ending—the final part of a film, book, story, etc.

Examples:

• zakończenie filmu = the ending of the film
• zakończenie książki = the ending of the book

It can also mean conclusion or completion, depending on context, but in this sentence it clearly means ending.

Because ale means but, and in Polish it normally introduces a new clause. Clauses joined by ale are separated by a comma.

So:

• Sam film jest ciekawy, ale zakończenie jest smutne.

This is similar to English, where a comma is also often used before but when joining two full clauses.

Yes, but it would mean something different.

• Ten film jest ciekawy = This film is interesting
• Sam film jest ciekawy = The film itself is interesting

So:

• ten points to which film
• sam adds emphasis: the film itself / just the film

You can even combine them:

• Sam ten film jest ciekawy
  = This film itself is interesting

But that is more specific and more emphatic.

Usually it means a sad ending, just like in English. That can mean:

• the events in the ending are sad
• the emotional tone of the ending is sad
• the ending makes the viewer feel sad

Polish works the same way here as English. The adjective smutne describes the ending’s character or emotional quality.

A simple approximate pronunciation is:

Sam film jest ciekawy, ale zakończenie jest smutne
→ sahm feem yest chye-KAH-vih, AH-leh zah-kohn-CHEN-yeh yest SMOOT-neh

A few useful sound notes:

• cie in ciekawy sounds roughly like chye
• cz sounds like English ch
• nie in zakończenie sounds like nye
• smutne has a clear t-n cluster: smoot-neh

If you want more natural rhythm, stress usually falls on the second-to-last syllable:

• cieKAwy
• zakońCZEnie
• SMUTne

Not perfectly.

A very literal translation would be:

• The film itself is interesting, but the ending is sad.

That works well in English, but Polish and English do not always line up word for word.

For example:

• sam does not always equal a single English word
• sometimes it is best translated as itself
• sometimes as alone
• sometimes just as emphasis

So it is better to understand the structure and function, not just memorize a word-for-word match.