Nem ugyanazt a filmet nézzük, de ugyanaz a zene tetszik nekünk.

Ugyanaz means the very same one or identical.

So:

• ugyanaz a film = the same movie
• ugyanolyan film = a similar kind of movie / the same type of movie

That distinction matters a lot:

• Nem ugyanazt a filmet nézzük = we are not watching one identical movie
• If you said Nem ugyanolyan filmet nézünk, that would mean we are not watching similar kinds of movies

So in your sentence, ugyanaz is the correct choice because it is talking about identity, not similarity.

Because the grammatical role is different in the two clauses.

In Nem ugyanazt a filmet nézzük:

• ugyanazt a filmet is the direct object
• direct objects take the accusative
• that is why you see -t

In de ugyanaz a zene tetszik nekünk:

• ugyanaz a zene is the subject
• subjects are in the basic form, with no accusative ending

So:

• ugyanazt a filmet = the same movie as object
• ugyanaz a zene = the same music as subject

This is normal in Hungarian with structures like ez a könyv, az a ház, and also ugyanaz a film.

When such a phrase gets a case ending, the case can appear on both the first element and the noun:

• ugyanaz a film
• ugyanazt a filmet

So here:

• ugyanazt = same-ACC
• filmet = movie-ACC

This kind of matching is a regular feature of Hungarian. It may feel redundant from an English perspective, but it is completely natural in Hungarian.

Because Hungarian has two conjugations:

• indefinite conjugation
• definite conjugation

You use the definite conjugation when the verb has a definite direct object.

Here the object is definite:

• ugyanazt a filmet = the same movie

So the verb must be definite:

• nézzük = we watch it / we are watching the ...
• not nézünk, which would be used without a definite object

Compare:

• Filmet nézünk. = We are watching a movie / movies.
• A filmet nézzük. = We are watching the movie.

Because Hungarian usually drops subject pronouns when the verb ending already makes the subject clear.

Nézzük already tells you:

• néz- = watch
• -jük / -ük = we in the definite conjugation

So mi is not necessary.

Hungarian only adds the pronoun if it is needed for emphasis or contrast:

• Mi nem ugyanazt a filmet nézzük. = We are not watching the same movie.

Without emphasis, just nézzük is enough.

Because tetszik works differently from English like.

Literally, tetszik means something like:

• is pleasing
• appeals

So:

• ugyanaz a zene tetszik nekünk

is structurally closer to:

• the same music is pleasing to us

This is one of the most important things for English speakers to get used to:

• in English: we like the music
• in Hungarian: the music pleases us

That is why a zene is the subject, and nekünk means to us.

Nekünk means to us.

It is the dative form of mi:

• mi = we
• nekünk = to us

With tetszik, the person who experiences the liking is often expressed in the dative:

• tetszik nekem = I like it / it pleases me
• tetszik neked = you like it
• tetszik nekünk = we like it

Yes, it can sometimes be omitted if the context already makes it clear:

• Ugyanaz a zene tetszik.

But then the sentence no longer explicitly says to whom it is pleasing. In your sentence, nekünk makes that clear.

Because Hungarian word order is strongly connected to focus and emphasis, not just grammar.

In Nem ugyanazt a filmet nézzük, the phrase ugyanazt a filmet is highlighted. The idea is:

• it is not the same movie that we are watching

This fits the contrast with the second clause:

• not the same movie
• but the same music

So the sentence is organized around contrast.

A version like Nem nézzük ugyanazt a filmet is possible in some contexts, but it sounds less like a neat contrastive statement and more like a straightforward negation of the action.

In your sentence, the chosen order is very natural because it sets up the contrast with de ugyanaz a zene...

Because the subject is singular:

• ugyanaz a zene = the same music

Since zene is singular, the verb is singular too:

• a zene tetszik

If the subject were plural, the verb would be plural:

• ugyanazok a dalok tetszenek nekünk = we like the same songs

So tetszik agrees with zene, not with nekünk.

A is the Hungarian definite article, equivalent to English the.

So:

• a film = the movie
• a zene = the music

In this sentence, the nouns are definite, and ugyanaz normally appears with the article in this kind of structure:

• ugyanaz a film
• ugyanaz a zene

When the noun is accusative, the article stays the same:

• ugyanazt a filmet

Also note that Hungarian chooses a or az based on the sound that follows:

• a film
• az alma

Since film and zene begin with consonant sounds, the article is a.

More or less, yes.

A more word-for-word breakdown would be:

• Nem = not
• ugyanazt a filmet = the same movie-ACC
• nézzük = we watch
• de = but
• ugyanaz a zene = the same music
• tetszik = is pleasing / appeals
• nekünk = to us

So a literal English-style unpacking would be:

• We are not watching the same movie, but the same music pleases us.

That sounds a bit unnatural in English, but it reflects the Hungarian structure quite well.